[Unreleased]

Correctly serialize nested superscripts, e.g. x^{y^z}.
The result of evaluation a Hold expression is now the expression itself.
To prevent evaluation of an expression temporarily, use the Unevaluated function. The result of evaluating an Unevaluated expression is its argument.
The type of a Hold expression was incorrectly returned as string. It now returns the type of its argument.
The statistics function (Mean, Median, Variance, StandardDeviation, Kurtosis, Skewness, Mode, Quartiles and InterQuartileRange) now accept as argument either a collection or a sequence of values.
```
ce.parse("\\mathrm{Mean}([7, 2, 11])").evaluate().print();
// -> 20/3
ce.parse("\\mathrm{Mean}(7, 2, 11)").evaluate().print();
// -> 20/3
```
The Variance and StandardDeviation functions now have variants for population statistics, PopulationVariance and PopulationStandardDeviation. The default is to use sample statistics.
```
ce.parse("\\mathrm{PopulationVariance}([7, 2, 11])").evaluate().print();
// -> 13.555
ce.parse("\\mathrm{Variance}([7, 2, 11])").evaluate().print();
// -> 20.333
```

The statistics function can now be compiled to JavaScript:

const code = ce.parse("\\mathrm{Mean}(7, 2, 11)").compile();
console.log(code());
// -> 13.555

The statistics function calculate either using machine numbers or bignums depending on the precision. The precision can be set with the precision property of the Compute Engine.
The argument of compiled function is now optional.

Compiled expressions can now reference external JavaScript functions. For example:

ce.defineFunction('Foo', {
  signature: 'number -> number',
  evaluate: ([x]) => ce.box(['Add', x, 1]),
});

const fn = ce.box(['Foo', 3]).compile({
  functions: { Foo: (x) => x + 1 },
})!;

console.info(fn());
// -> 4

ce.defineFunction('Foo', {
  signature: 'number -> number',
  evaluate: ([x]) => ce.box(['Add', x, 1]),
});

function foo(x) {
  return x + 1;
}

const fn = ce.box(['Foo', 3]).compile({
  functions: { Foo: foo },
})!;

console.info(fn());
// -> 4

Additionally, functions can be implicitly imported (in case they are needed by other JavaScript functions):

ce.defineFunction('Foo', {
  signature: 'number -> number',
  evaluate: ([x]) => ce.box(['Add', x, 1]),
});

function bar(x, y) {
  return x + y;
}

function foo(x) {
  return bar(x, 1);
}


const fn = ce.box(['Foo', 3]).compile({
  functions: { Foo: 'foo' },
  imports: [foo, bar],
})!;

console.info(fn());
// -> 4

Compiled expression can now include an arbitrary preamble (JavaScript source) that is executed before the compiled function is executed. This can be used to define additional functions or constants.

ce.defineFunction('Foo', {
  signature: 'number -> number',
  evaluate: ([x]) => ce.box(['Add', x, 1]),
});

const code = ce.box(['Foo', 3]).compile({
  preamble: "function Foo(x) { return x + 1};",
});

0.26.4 2024-10-17

#201 Identifiers of the form A_\text{1} were not parsed correctly.
#202 Fixed serialization of integrals and bigops.

0.26.3 2024-10-17

Correctly account for fractionalDigits when formatting numbers.
#191 Correctly handle \\lnot\\forall and \\lnot\\exists.
#206 The square root of 1000000 was canonicalized to 0.
#207 When a square root with a literal base greater than 1e6 was preceded by a non-integer literal number, the literal number was ignored during canonicalization.
#208 #204 Correctly evaluate numeric approximation of roots, e.g. \\sqrt[3]{125}.
#205 1/ln(0) was incorrectly evaluated to 1. It now returns 0.

0.26.1 2024-10-04

Issues Resolved

#194 Correctly handle the precedence of unary negate, for example in -5^{\frac12} or -5!.
When using a function definition with ce.declare(), do not generate a runtime error.

New Features and Improvements

Added .expand() method to boxed expression. This method expands the expression, for example ce.parse("(x+1)^2").expand() will return x^2 + 2x + 1.

0.26.0 2024-10-01

Breaking Changes

The property expr.head has been deprecated. Use expr.operator instead. expr.head is still supported in this version but will be removed in a future update.
The MathJSON utility functions head() and op() have been renamed to operator() and operand() respectively.
The methods for algebraic operations (add, div, mul, etc...) have been moved from the Compute Engine to the Boxed Expression class. Instead of calling ce.add(a, b), call a.add(b).

Those methods also behave more consistently: they apply some additional simplication rules over canonicalization. For example, while ce.parse('1 + 2') return ["Add", 1, 2], ce.box(1).add(2) will return 3.
The ce.numericMode option has been removed. Instead, set the ce.precision property to the desired precision. Set the precision to "machine" for machine precision calculations (about 15 digits). Set it to "auto" for a default of 21 digits. Set it to a number for a greater fixed precision.
The MathJSON Dictionary element has been deprecated. Use a Dictionary expression instead.
The ExtendedRealNumbers, ExtendedComplexNumbers domains have been deprecated. Use the RealNumbers and ComplexNumbers domains instead.
The "Domain" expression has been deprecated. Use types instead (see below).
Some BoxedExpression properties have been removed:
- Instead of expr.isZero, use expr.is(0).
- Instead of expr.isNotZero, use !expr.is(0).
- Instead of expr.isOne, use expr.is(1).
- Instead of expr.isNegativeOne, use expr.is(-1).
The signature of ce.declare() has changed. In particular, the N handler has been replaced with evaluate.

// Before
ce.declare('Mean', {
  N: (ce: IComputeEngine): BoxedExpression => {
    return ce.number(1);
  },
});

// Now
ce.declare('Mean', { evaluate: (ops, { engine }) => ce.number(1) });

New Features and Improvements

New Simplification Engine

The way expressions are simplified has been completely rewritten. The new engine is more powerful and more flexible.

The core API remains the same: to simplify an expression, use expr.simplify().

To use a custom set of rules, pass the rules as an argument to simplify():
```
expr.simplify({rules: [
  "|x:<0| -> -x",
  "|x:>=0| -> x",
]});
```
There are a few changes to the way rules are represented. The priority property has been removed. Instead, rules are applied in the order in which they are defined.

A rule can also now be a function that takes an expression and returns a new expression. For example:
```
expr.simplify({rules: [
  (expr) => {
    if (expr.operator !== 'Abs') return undefined;
    const x = expr.args[0];
    return x.isNegative ? x.negate() : expr;
  }
]});
```
This can be used to perform more complex transformations at the cost of more verbose JavaScript code.

The algorithm for simplification has been simplified. It attempts to apply each rule in the rule set in turn, then restarts the process until no more rules can be applied or the result of applying a rule returns a previously seen expression.

Function definitions previously included a simplify handler that could be used to perform simplifications specific to this function. This has been removed. Instead, use a rule that matches the function and returns the simplified expression.
Types

Previously, an expression was associated with a domain such as RealNumbers or ComplexNumbers. This has been replaced with a more flexible system of types.

A type is a set of values that an expression can take. For example, the type real is the set of real numbers, the type integer is the set of integers,

The type of an expression can be set with the type property. For example:
```
const expr = ce.parse('\\sqrt{-1}');
console.info(expr.type); // -> imaginary
```
The type of a symbol can be set when declaring the symbol. For example:
```
ce.declare('x', 'imaginary');
```
In addition to primitive types, the type system supports more complex types such union types, intersection types, and function types.

For example, the type real|imaginary is the union of the real and imaginary numbers.

When declaring a function, the type of the arguments and the return value can be specified. For example, to declare a function f that takes two integers and returns a real number:
```
ce.declare('f', '(integer, integer) -> real');
```
The sets of numbers are defined as follows:
- number - any number, real or complex, including NaN and infinity
- non_finite_number - NaN or infinity
- real
- finite_real - finite real numbers (exclude NaN and infinity)
- imaginary - imaginary numbers (complex numbers with a real part of 0)
- finite_imaginary
- complex - complex numbers with a real and imaginary part not equal to 0
- finite_complex
- rational
- finite_rational
- integer
- finite_integer
To check the type of an expression, use the isSubtypeOf() method. For example:
```
let expr = ce.parse('5');
console.info(expr.type.isSubtypeOf('rational')); // -> true
console.info(expr.type.isSubtypeOf('integer')); // -> true

expr = ce.parse('\\frac{1}{2}');
console.info(expr.type.isSubtypeOf('rational')); // -> true
console.info(expr.type.isSubtypeOf('integer')); // -> false
```
As a shortcut, the properties isReal, isRational, isInteger are available on boxed expressions. For example:
```
let expr = ce.parse('5');
console.info(expr.isInteger); // -> true
console.info(expr.isRational); // -> true
```
They are equivalent to expr.type.isSubtypeOf('integer') and expr.type.isSubtypeOf('rational') respectively.

To check if a number has a non-zero imaginary part, use:
```
let expr = ce.parse('5i');
console.info(expr.isNumber && expr.isReal === false); // -> true
```
Collections

Support for collections has been improved. Collections include List, Set, Tuple, Range, Interval, Linspace and Dictionary.

It is now possible to check if an element is contained in a collection using an Element expression. For example:
```
let expr = ce.parse('[1, 2, 3]');
ce.box(['Element', 3, expr]).print(); // -> True
ce.box(['Element', 5, expr]).print(); // -> False
```
To check if a collection is a subset of another collection, use the Subset expression. For example:
```
ce.box(['Subset', 'Integers', 'RealNumbers']).print(); // -> True
```
Collections can also be compared for equality. For example:
```
let set1 = ce.parse('\\lbrace 1, 2, 3 \\rbrace');
let set2 = ce.parse('\\lbrace 3, 2, 1 \\rbrace');
console.info(set1.isEqual(set2)); // -> true
```
There are also additional convenience methods on boxed expressions:
- expr.isCollection
- expr.contains(element)
- expr.size
- expr.isSubsetOf(other)
- expr.indexOf(element)
- expr.at(index)
- expr.each()
- expr.get(key)
Exact calculations

The Compute Engine has a new backed for numerical calculations. The new backed can handle arbitrary precision calculations, including real and complex numbers. It can also handle exact calculations, preserving calculations with rationals and radicals (square root of integers). For example 1/2 + 1/3 is evaluated to 5/6 instead of 0.8(3).

To get an approximate result, use the N() method, for example ce.parse("\\frac12 + \\frac13").N().

Previously the result of calculations was not always an exact number but returned a numerical approximation instead.

This has now been improved by introducing a NumericValue type that encapsulates exact numbers and by doing all calculations in this type. Previously the calculations were handled manually in the various evaluation functions. This made the code complicated and error prone.

A NumericValue is made of:
- an imaginary part, represented as a fixed-precision number
- a real part, represented either as a fixed or arbitrary precision number or as the product of a rational number and the square root of an integer.
For example:
- 234.567
- 1/2
- 3√5
- √7/3
- 4-3i
While this is a significant change internally, the external API remains the same. The result of calculations should be more predictable and more accurate.

One change to the public API is that the expr.numericValue property is now either a machine precision number or a NumericValue object.
Rule Wildcards

When defining a rule as a LaTeX expression, single character identifiers are interpreted as wildcards. For example, the rule x + x -> 2x will match any expression with two identical terms. The wildcard corresponding to x is _x.

It is now possible to define sequence wildcards and optional sequence wildcards. Sequence wildcards match 1 or more expressions, while optional sequence wildcards match 0 or more expressions.

They are indicated in LaTeX as ...x and ...x? respectively. For example:
```
expr.simplify("x + ...y -> 2x");
```
If expr is a + b + c the rule will match and return 2a
```
expr.simplify("x + ...y? -> 3x");
```
If expr is a + b + c the rule will match and return 3a. If expr is a the rule will match and return 3a.
Conditional Rules

Rules can now include conditions that are evaluated at runtime. If the condition is not satisfied, the rules does not apply.

For example, to simplify the expression |x|:
```
expr.simplify({rules: [
  "|x_{>=0}| -> x",
  "|x_{<0}| -> -x",
]});
```
The condition is indicated as a subscript of the wildcard. The condition can be one of:
- boolean - a boolean value, True or False
- string - a string of characters
- number - a number literal
- symbol
- expression
- numeric - an expression that has a numeric value, i.e. 2√3, 1/2, 3.14
- integer - an integer value, -2, -1, 0, 1, 2, 3, ...
- natural - a natural number, 0, 1, 2, 3, ...
- real - real numbers, including integers
- imaginary - imaginary numbers, i.e. 2i, 3√-1 (not including real numbers)
- complex - complex numbers, including real and imaginary
- rational - rational numbers, 1/2, 3/4, 5/6, ...
- irrational - irrational numbers, √2, √3, π, ...
- algebraic - algebraic numbers, rational and irrational
- transcendental - transcendental numbers, π, e, ...
- positive - positive real numbers, > 0
- negative - negative real numbers, < 0
- nonnegative - nonnegative real numbers, >= 0
- nonpositive - nonpositive real numbers, <= 0
- even - even integers, 0, 2, 4, 6, ...
- odd - odd integers, 1, 3, 5, 7, ...
- prime :A000040 - prime numbers, 2, 3, 5, 7, 11, ...
- composite :A002808 - composite numbers, 4, 6, 8, 9, 10, ...
- notzero - a value that is not zero
- notone - a value that is not one
- finite - a finite value, not infinite
- infinite
- constant
- variable
- function
- operator
- relation - an equation or inequality
- equation
- inequality
- vector - a tensor of rank 1
- matrix - a tensor of rank 2
- list - a collection of values
- set - a collection of unique values
- tuple - a fixed length list
- single - a tuple of length 1
- pair - a tuple of length 2
- triple - a tuple of length 3
- collection - a list, set, or tuple
- tensor - a nested list of values of the same type
- scalar - not a tensor or list
or one of the following expressions:
- >0' -> positive,
- \gt0' -> positive,
- <0' -> negative,
- \lt0' -> negative,
- >=0' -> nonnegative,
- \geq0' -> nonnegative,
- <=0' -> nonpositive,
- \leq0' -> nonpositive,
- !=0' -> notzero,
- \neq0' -> notzero,
- !=1' -> notone,
- \neq1' -> notone,
- \in\Z' -> integer,
- \in\mathbb{Z}' -> integer,
- \in\N' -> natural,
- \in\mathbb{N}' -> natural,
- \in\R' -> real,
- \in\mathbb{R}' -> real,
- \in\C' -> complex,
- \in\mathbb{C}' -> complex,
- \in\Q' -> rational,
- \in\mathbb{Q}' -> rational,
- \in\Z^+' -> integer,positive,
- \in\Z^-' -> intger,negative,
- \in\Z^*' -> nonzero,
- \in\R^+' -> positive,
- \in\R^-' -> negative,
- \in\R^*' -> real,nonzero,
- \in\N^*' -> integer,positive,
- \in\N_0' -> integer,nonnegative,
- \in\R\backslash\Q' -> irrational,
More complex conditions can be specified following a semi-colon, for example:
```
expr.simplify({x -> 2x; x < 10});
```
Note that this syntax complements the existing rule syntax, and can be used together with the existing, more verbose, rule syntax.
```
expr.simplify({rules: [
  {match: "x + x", replace: "2x", condition: "x < 10"}
]});
```
This advanced syntax can specify more complex conditions, for example above the rule will only apply if x is less than 10.
Improved results for Expand. In some cases the expression was not fully expanded. For example, 4x(3x+2)-5(5x-4) now returns 12x^2 - 17x + 20. Previously it returned 4x(3x+2)+25x-20.
AsciiMath serialization The expr.toString() method now returns a serialization of the expression using the AsciiMath format.

The serialization to AsciiMath can be customized using the toAsciiMath() method. For example:
```
console.log(ce.box(['Sigma', 2]).toAsciiMath({functions: {Sigma: 'sigma'}}));
// -> sigma(2)
```
The tolerance can now be specified with a value of "auto" which will use the precision to determine a reasonable tolerance. The tolerance is used when comparing two numbers for equality. The tolerance can be specified with the ce.tolerance property or in the Compute Engine constructor.
Boxed expressions have some additional properties:
- expr.isNumberLiteral - true if the expression is a number literal.This is equivalent to checking if expr.numericValue is not null.
- expr.re - the real part of the expression, if it is a number literal, undefined if not a number literal.
- expr.im - the imaginary part of the expression, if it is a number literal, undefined if not a number literal.
- expr.bignumRe - the real part of the expression as a bignum, if it is a number literal, undefined if not a number literal or a bignum representation is not available.
- expr.bignumIm - the imaginary part of the expression as a bignum, if it is a number literal, undefined if not a number literal or if a bignum representation is not available.
- expr.root() to get the root of the expression. For example, expr.root(3) will return the cube root of the expression.
- Additionally, the relational operators (expr.isLess(), expr.isEqual(), etc...) now accept a number argument. For example, expr.isGreater(1) will return true if the expression is greater than 1.
Added LaTeX syntax to index collections. If a is a collection:
- a[i] is parsed as ["At", "a", "i"].
- a[i,j] is parsed as ["At", "a", "i", "j"].
- a_i is parsed as ["At", "a", "i"].
- a_{i,j} is parsed as ["At", "a", "i", "j"].
Added support for Kronecker delta notation, i.e. \delta_{ij}, which is parsed as ["KroneckerDelta", "i", "j"] and is equal to 1 if i = j and 0 otherwise.

When a single index is provided the value of the function is 1 if the index is 0 and 0 otherwise

When multiple index are provided, the value of the function is 1 if all the indexes are equal and 0 otherwise.
Added support for Iverson Bracket notation, i.e. [a = b], which is parsed as ["Boole", ["Equal", "a", "b"]] and is equal to 1 if its argument is true and 0 otherwise. The argument is expected to be a relational expression.

Implemented Unique and Tally on collections. Unique returns a collection with only the unique elements of the input collection, and Tally returns a collection with the count of each unique element.

console.log(ce.box(['Unique', ['List', 1, 2, 3, 1, 2, 3, 4, 5]]).value);
// -> [1, 2, 3, 4, 5]

console.log(ce.box(['Tally', ['List', 1, 2, 3, 1, 2, 3, 4, 5]]).value);
// -> [['List', 1, 2, 3, 4, 5], ['List', 2, 2, 2, 1, 1]]

Implemented the Map, Filter and Tabulate functions. These functions can be used to transform collections, for example:

// Using LaTeX
console.log(ce.parse('\\mathrm{Map}([3, 5, 7], x \\mapsto x^2)').toString());
// -> [9, 25, 49]

// Using boxed expressions
console.log(
  ce.box(['Map', ['List', 3, 5, 7], ['Square', '_']]).value
);
// -> [9, 25, 49]

console.log(ce.box(['Tabulate',['Square', '_'], 5]).value);
// -> [1, 4, 9, 16, 25]

Tabulate can be used with multiple indexes. For example, to generate a 4x4 unit matrix:

console.log(ce.box(['Tabulate', ['If', ['Equal', '_1', '_2'], 1, 0]], 4, 4).value);
// -> [[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]

// Using the Kronecker delta notation:
console.log(ce.parse('\\mathrm{Tabulate}(i, j \\mapsto \\delta_{ij}, 4, 4)').value);
// -> [[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]

Added Random function. ["Random"] returns a real pseudo-random number betwen 0 and 1. ["Random", 10] returns an integer between 0 and 9, ["Random", 5, 10] returns an integer between 5 and 10.
Extended the definition of expr.isConstant. Previously, it only applied to symbols, e.g. Pi. Now it apply to all expressions. expr.isConstant is true if the expression is a number literal, a symbol with a constant value, or a pure function with constant arguments.
The boxed expression properties isPositive, isNegative, isNonNegative, isNonPositive, isZero, isNotZero now return a useful value for most function expressions. For example, ce.parse('|x + 1|').isPositive is true.

If the value cannot be determined, the property will return undefined. For example, ce.parse('|x + 1|').isZero is undefined.

If the expression is not a real number, the property will return NaN. For example, ce.parse('i').isPositive is NaN.
Added Choose function to compute binomial coefficients, i.e. Choose(5, 2) is equal to 10.
The fallback for non-constructible complex values of trigonometric functions is now implemented via rules.
The canonical order of the arguments has changed and should be more consistent and predictable. In particular, for polynomials, the monomial order is now degrevlex.
Canonical expressions can now include a Root expression. For example, the canonical form of \\sqrt[3]{5} is ["Root", 5, 3]. Previously, these were represented as ["Power", 5, ["Divide", 1, 3]].
The function definitions no longer have a N handler. Instead the evaluate handler has an optional {numericApproximation} argument.

Issues Resolved

#188 Throw an error when invalid expressions are boxed, for example ce.box(["Add", ["3"]]).
Some LaTeX renderer can't render \/, so use / instead.
When definitions are added to the LaTeX dictionary, they now take precedence over the built-in definitions. This allows users to override the built-in definitions.
Improved parsing of functions, including when a mixture of named and positional arguments are used.
#175 Matching some patterns when the target had not enough operands would result in a runtime error.

0.25.1 2024-06-27

Issues Resolved

#174 Fixed some simplifications, such as \frac{a^n}{a^m} = a^{n-m)

New Features

Rules can be defined using a new shorthand syntax, where each rule is a string of LaTeX:
```
expr.simplify(["\\frac{x}{x} -> 1", "x + x -> 2x"]);
```

Single letter variables are assumed to be wildcards, so x is interpreted as the wildcard _x.

Additionally, the expanded form can also include LaTeX strings. The previous syntax using expressions can still be used, and the new and old syntax can be mixed.

For example:

expr.simplify([
  {
    match: "\\frac{x}{x}",
    replace: "1"
  },
  {
    match: ["Add", "x", "x"],
    replace: "2x"
  }
]);

The condition function can also be expressed as a LaTeX string.

  expr.simplify([ { match: "\\frac{x}{x}", replace: 1, condition: "x != 0" }, ]);

The shorthand syntax can be used any where a ruleset is expected, including with the ce.rule() function.

A new ce.getRuleSet() method gives access to the built-in rules.
#171 The Subtract and Divide function can now accept an arbitrary number of arguments. For example, ["Subtract", 1, 2, 3] is equivalent to ["Subtract", ["Subtract", 1, 2], 3].

0.25.0 2024-06-25

Breaking Changes

The canonical form of expressions has changed. It is now more consistent and simpler and should produce more predictable results.

For example, previously ce.parse("1-x^2") would produce ["Subtract", 1, ["Square", "x"]].

While this is a readable form, it introduces some complications when manipulating the expression: both the Subtract and Square functions have to be handled, in addition to Add and Power.

The new canonical form of this expression is ["Add", 1, ["Negate", ["Power", "x", 2]]]. It is a bit more verbose, but it is simpler to manipulate.
The ce.serialize() method has been replaced with expr.toLatex() and expr.toMathJson(). The ce.latexOptions and ce.jsonSerializationOptions properties have been removed. Instead, pass the formating options directly to the toLatex() and toMathJson() methods. The ce.parse() method now takes an optional argument to specify the format of the input string.
The default JSON serialization of an expression has changed.

Previously, the default JSON serialization, accessed via the .json property, had some transformations applied to it (sugaring) to make the JSON more human readable.

For example, ce.parse("\frac12").json would return the symbol "Half" instead of ["Divide", 1, 2].

However, this could lead to some confusion when manipulating the JSON directly. Since the JSON is intended to be used by machine more than humans, these additional transformations have been removed.

The expr.json property now returns the JSON representing the expression, without any transformations.

To get a version of JSON with some transformations applied use the ce.toMathJson() function.
```
expr = ce.box(["Subtract", 1, ["Square", "x"]]);
console.log(expr.json);
// -> ["Add", 1, ["Negate", ["Power", "x", 2]]]
expr.toMathJson()
// -> ["Subtract", 1, ["Square", "x"]]
expr.toMathJson({exclude: "Square"})
// -> ["Subtract", 1, ["Power", "x", 2]]
```
In practice, the impact of both of these changes should be minimal. If you were manipulating expressions using BoxedExpression, the new canonical form should make it easier to manipulate expressions. You can potentially simplify your code by removing special cases for functions such as Square and Subtract.

If you were using the JSON serialization directly, you may also be able to simplify you code since the default output from expr.json is now more consistent and simpler.
The name of some number formatting options has changed. The number formatting options are an optional argument of ce.parse() and ce.toLatex(). See the
NumberFormat and NumberSerializationFormat types.
The values +infinity, -infinity and NaN are now represented preferably with the symbols PositiveInfinity, NegativeInfinity and NaN respectively. Previously they were represented with numeric values, i.e. {num: "+Infinity"}, {num: "-Infinity"} and {num: "NaN"}. The numeric values are still supported, but the symbols are preferred.
The method expr.isNothing has been removed. Instead, use expr.symbol === "Nothing".

New Features

When serializing to LaTeX, the output can be "prettified". This involves modifying the LaTeX output to make it more pleasant to read, for example:
- a+\\frac{-b}{c} -> a-\\frac{b}{c}
- a\\times b^{-1} -> \\frac{a}{b}
- \\frac{a}{b}\\frac{c}{d} -> \\frac{a\\cdot c}{b\\cdot d}
- --2 -> 2
This is on by default and can be turned off by setting the prettify option to false. For example:
```
ce.parse("a+\\frac{-b}{c}").toLatex({prettify: true})
// -> "a-\\frac{b}{c}"
ce.parse("a+\\frac{-b}{c}").toLatex({prettify: false})
// -> "a+\\frac{-b}{c}"
```
Numbers can have a different digit group length for the whole and fractional part of a number. For example, ce.toLatex(ce.parse("1234.5678"), {digitGroup: [3, 0]}) will return 1\,234.5678.
Numbers can now be formatted using South-East Asian Numbering System, i.e. lakh and crore. For example:
```
ce.toLatex(ce.parse("12345678"), {digitGroup: "lakh"})
// -> "1,23,45,678"
```
Expressions with Integrate functions can now be compiled to JavaScript. The compiled function can be used to evaluate the integral numerically. For example:
```
const f = ce.parse("\\int_0^1 x^2 dx");
const compiled = f.compile();
console.log(compiled()); // -> 0.33232945619482307
```
#82 Support for angular units. The default is radians, but degrees can be used by setting ce.angularUnit = "deg". Other possible values are "grad" and "turn". This affects how unitless numbers with a trigonometric function are interpreted. For example, sin(90) will return 1 when ce.angularUnit is "deg", 0.8939966636005579 when ce.angularUnit is "grad" and 0 when ce.angularUnit is "turn".
Added expr.map(fn) method to apply a function to each subexpression of an expression. This can be useful to apply custom canonical forms and compare two expressions.
An optional canonical form can now be specified with the ce.function().

Issues Resolved

#173 Parsing 1++2 would result in an expression with a PreIncrement function. It is now correctly parsed as ["Add", 1, 2].
#161 Power expressions would not be processed when their argument was a Divide expression.
#165 More aggressive simplification of expressions with exponent greater than 3.
#169 Calculating a constant integral (and integral that did not depend on the variable) would result in a runtime error.
#164 Negative mixed fractions (e.g. -1\frac23) are now parsed correctly.
#162 Numeric evaluation of expressions with large exponents could result in machine precision numbers instead of bignum numbers.
#155 The expression ["Subtract", ["Multiply", 0.5, "x"], ["Divide", "x", 2]] will now evaluate to 0.
#154 In some cases, parsing implicit argument of trig function return more natural results, for example \cos a \sin b is now parsed as (\cos a)(\sin b) and not \cos (a \sin b).
#147 The associativity of some operators, including / was not applied correctly, resulting in unexpected results. For example, 1/2/3 would be parsed as ["Divide", 1, ["Divide", 2, 3]] instead of ["Divide", ["Divide", 1, 2], 3].
#146 When parsing an expression like x(x+1) where x is an undeclared symbol, do not infer that x is a function. Instead, infer that x is a variable and that the expression is a product.
#145 The expression ["Or", "False", "False"], that is when all the arguments are False, is now evaluates to False.
Fixed canonical form of e^x^2, and more generally apply power rule in more cases.
Added missing "Sech" and "Csch" functions.
The digit grouping serializing would place the separator in the wrong place for some numbers.
The avoidExponentsInRange formating option would not always avoid exponents in the specified range.

0.24.0 2024-02-23

Issues Resolved

Fix parsing of very deeply nested expressions.
Correctly apply rules to deeply nested expressions.
expr.print() now correctly prints the expression when using the minified version of the library.
expr.isEqual() now correctly compares equalities and inequalities.
expr.match() has been improved and works correctly in more cases. The signature of the match function has been changed so that the pattern is the first argument, i.e. instead of pattern.match(expr) use expr.match(pattern).
Fix expr.print() when using the minified version of the library.
#142 Accept complex expressions as the subcript of \ln and \log in LaTeX.
#139 Parse quantifiers \forall and \exists in LaTeX.

0.23.1 2024-01-27

Issues Resolved

Using a custom canonical order of "Multiply" would not distribute the Negate function.
#141 The canonical form "Order" was applied to non-commutative functions.

0.23.0 2024-01-01

New Features

Added ExpandAll function to expand an expression recursively.
Added Factor function to factor an expression.
Added Together function to combine rational expressions into a single fraction.

Issues Resolved

The expression \frac5 7 is now parsed correctly as \frac{5}{7} instead of \frac{5}{}7.
Do not sugar non-canonical expression. Previously, ce.parse('\\frac{1}{2}', {canonical: false}) would return Half instead of ['Divide', '1', '2'].
#132 Attempting to set a value to 0 with ce.defineSymbol("count", {value: 0}) would fail: the symbol would be undefined.
Correctly evaluate power expressions in some cases, for example (\sqrt2 + \sqrt2)^2.
Comparison of expressions containing non-exact numbers could fail. For example: 2(13.1+3.1x) and 26.2+6.2x would not be considered equal.

Improvements

Significant improvements to symbolic computation. Now, boxing, canonicalization and evaluation are more consistent and produce more predictable results.
Adedd the \neg command, synonym for \lnot -> Not.
Relational expressions (inequalities, etc...) are now properly factored.
Integers are now factored when simplifying, i.e. 2x = 4x -> x = 2x.

0.22.0 2023-11-13

Breaking Changes

Rule Syntax

The syntax to describe rules has changed. The syntax for a rule was previously a tuple [lhs, rhs, {condition} ]. The new syntax is an object with the properties match, replace and condition. For example:
- previous syntax: [["Add", "_x", "_x"], ["Multiply", 2, "_x"]]
- new syntax: {match: ["Add", "_x", "_x"], replace: ["Multiply", 2, "_x"]}
The condition property is optional, and is either a boxed function or a JavaScript function. For example, to add a condition that checks that _x is a number literal:
```
{
  match: ["Add", "_x", "_x"],
  replace: ["Multiply", 2, "_x"],
  condition: ({_x}) => _x.isNumberLiteral
}
```
CanonicalForm

The CanonicalOrder function has been replaced by the more flexible CanonicalForm function. The CanonicalForm function takes an expression and a list of transformations to apply. To apply the same transformations as CanonicalOrder, use:
```
['CanonicalForm', expr, 'Order']
```
These canonical forms can also be specified with box() and parse() options:
```
ce.box(expr, { canonical: "Order" });
ce.parse("x^2 + 2x + 1", { canonical: "Order" });
```

Work In Progress

Linear algebra functions: Rank, Shape,Reshape, Flatten, Determinant, Trace, Transpose, ConjugateTranspose, Inverse. See the Linear Algebra reference guide. Some of these function may not yet return correct result in all cases.

New Features

Added a expr.print() method as a synonym for console.log(expr.toString()).
Added an exact option (false by default) to the expr.match() pattern matching method. When true some additional patterns are automatically recognized, for example, x will match ["Multiply", '_a', 'x'] when exact is false, but not when exact is true.

Improvements

The equation solver used by expr.solve() has been improved and can now solve more equations.
The pattern matching engine has been improved and can now match more expressions, including sequences for commutative functions.

0.21.0 2023-11-02

New Features

#125 Parse and serialize environemnts, i.e. \begin{matrix} 1 & 2 \\ 3 & 4 \end{matrix} will be parsed as ["Matrix", ["List", ["List", 1, 2], ["List", 3, 4]]].

A new section on Linear Algebra has some details on the supported formats.

The linear algebra operations are limited at the moment, but will be expanded in the future.
Added IsSame function, which is the function expression corresponding to expr.isSame().
~~Added CanonicalOrder function, which sorts the arguments of commutative functions into canonical order. This is useful to compare two non-canonical expressions for equality.~~

ce.box(["CanonicalOrder", ["Add", 1, "x"]]).isSame(
  ce.box(["CanonicalOrder", ["Add", "x", 1]])
);
// -> true

Issue Resolved

When evaluating a sum (\sum) with a bound that is not a number, return the sum expression instead of an error.

0.20.2 2023-10-31

Issues Resolved

Fixed numerical evaluation of integrals and limits when parsed from LaTeX.

console.info(ce.parse("\\lim_{x \\to 0} \\frac{\\sin(x)}{x}").value);
// -> 1

console.info(ce.parse("\\int_{0}^{2} x^2 dx").value);
// -> 2.6666666666666665

0.20.1 2023-10-31

Issues Resolved

Fixed evaluation of functions with multiple arguments
Fixed compilation of some function assignments
Improved serialization of function assignment

0.20.0 2023-10-30

Breaking Changes

Architectural changes: the invisible operator is used to represent the multiplication of two adjacent symbols, i.e. 2x. It was previously handled during parsing, but it is now handled during canonicalization. This allows more complex syntactic structures to be handled correctly, for example f(x) := 2x: previously, the left-hand-side argument would have been parsed as a function application, while in this case it should be interpreted as a function definition.

A new InvisibleOperator function has been added to support this.

The applyInvisibleOperator parsing option has been removed. To support custom invisible operators, use the InvisibleOperator function.

Issues Resolved

#25 Correctly parse chained relational operators, i.e. a < b <= c
#126 Logic operators only accepted up to two arguments.
#127 Correctly compile Log with bases other than 10.
Correctly parse numbers with repeating patterns but no fractional digits, i.e. 0.(1234)
Correctly parse |1+|a|+2|

New Features and Improvements

Function assignment can now be done with this syntax: f(x) := 2x+1. This syntax is equivalent to f := x -> 2x+1.
Implement the Mod and Congruent function.
Correctly parse 11 \bmod 5 (Mod) and 26\equiv 11 \pmod5 (Congruent)
Better handle empty argument lists, i.e. f()
When a function is used before being declared, infer that the symbol is a function, e.g. f(12) will infer that f is a function (and not a variable f multiplied by 12)
When a constant is followed by some parentheses, don't assume this is a function application, e.g. \pi(3+n) is now parsed as ["Multiply", "Pi", ["Add", 3, "n"]] instead of ["Pi", ["Add", 3, "n"]]
Improved parsing of nested lists, sequences and sets.
Improved error messages when syntax errors are encountered during LaTeX parsing.
When parsing with the canonical option set to false, preserve more closely the original LaTeX syntax.
When parsing text strings, convert some LaTeX commands to Unicode, including spacing commands. As a result, ce.parse("\\text{dead\;beef}_{16}") correctly gets evaluated to 3,735,928,559.

0.19.1 2023-10-26

Issues Resolved

Assigning a function to an indentifier works correctly now, i.e.

ce.parse("\\operatorname{f} := x \\mapsto 2x").evaluate();

0.19.0 2023-10-25

Breaking Changes

The domain property of the function definition signature is deprecated and replaced with the params, optParams, restParam and result properties instead. The domain property is still supported for backward compatibility, but will be removed in a future version.

Issues Resolved

When invoking a declared function in a numeric operation, correctly infer the result type.

["Assign", "f", ["Add", "_", 1]]
["Add", ["f", 1], 1]
// -> 3

Previously a domain error was returned, now f is inferred to have a numeric return type.

Fixed a runtime error when inverting a fraction, i.e. \frac{3}{4}^{-1}
The tangent of π/2 now correctly returns ComplexInfinity.
The exact values of some constructible trigonometric operations (e.g. \tan 18\degree = \frac{\sqrt{25-10\sqrt5}}{5}) returned incorrect results. The unit test case was incorrect and did not detect the problem. The unit test case has been fixed and the returned values are now correct.

New Features

Implemented Union and Intersection of collections, for example:

["Intersection", ["List", 3, 5, 7], ["List", 2, 5, 9]]
// -> ["Set", 5]

["Union", ["List", 3, 5, 7], ["List", 2, 5, 9]]
// -> ["Set", 3, 5, 7, 2, 9]

Parse ranges, for example 1..5 or 1, 3..10. Ranges are collections and can be used anywhere collections can be used.
The functions Sum, Product, Min, Max, and the statistics functions (Mean, Median, Variance, etc...) now handle collection arguments: collections:
- ["Range"], ["Interval"], ["Linspace"] expressions
- ["List"] or ["Set"] expressions
- ["Tuple"], ["Pair"], ["Pair"], ["Triple"] expressions
- ["Sequence"] expressions
Most mathematical functions are now threadable, that is their arguments can be collections, for example:

["Sin", ["List", 0, 1, 5]]
// -> ["List", 0, 0.8414709848078965, -0.9589242746631385]

["Add", ["List", 1, 2], ["List", 3, 4]]
// -> ["List", 4, 6]

Added GCD and LCM functions

["GCD", 10, 5, 15]
// -> 5

["LCM", 10, 5, 15]
// -> 30

Added Numerator, Denominator, NumeratorDenominator functions. These functions can be used on non-canonical expressions.
Added Head and Tail functions which can be used on non-canonical expressions.
Added display-quotient and inline-quotient style for formatting of division expressions in LaTeX.

Improvements

Improved parsing of \degree command

ce.parse("30\\degree)
// -> ["Divide", "Pi", 6]

Improved interoperability with JavaScript: expr.value will return a JavaScript primitive (number, boolean, string, etc...) when possible. This is a more succinct version of expr.N().valueOf().

0.18.1 2023-10-16

Issues Resolved

Parsing of whole numbers while in rational mode would return incorrect results.
The ND function to evaluate derivatives numerically now return correct values.

ce.parse("\\mathrm{ND}(x \\mapsto 3x^2+5x+7, 2)").N();
// -> 17.000000000001

Improvements

Speed up NIntegrate by temporarily switching the numeric mode to machine while computing the Monte Carlo approximation.

0.18.0 2023-10-16

New Features

Expanded LaTeX dictionary with \max, \min, \sup, \inf and \lim functions
Added Supremum and Infimum functions
Compilation of Block expressions, local variables, return statements and conditionals If.
Added numerical evaluation of limits with Limit functions and NLimit functions, using a Richardson Extrapolation.

console.info(ce.parse("\\lim_{x\\to0} \\frac{\\sin x}{x}").N().json);
// -> 1

console.info(
  ce.box(["NLimit", ["Divide", ["Sin", "_"], "_"], 0]).evaluate().json
);
// -> 1

console.info(ce.parse("\\lim_{x\\to \\infty} \\cos \\frac{1}{x}").N().json);
// -> 1

Added Assign and Declare functions to assign values to symbols and declare symbols with a domain.
Block evaluations with local variables work now. For example:

ce.box(["Block", ["Assign", "c", 5], ["Multiply", "c", 2]]).evaluate().json;
// -> 10

When decimal numbers are parsed they are interpreted as inexact numbers by default, i.e. "1.2" -> {num: "1.2"}. To force the number to be interpreted as a rational number, set ce.latexOptions.parseNumbers = "rational". In that case, "1.2" -> ["Rational", 12, 10], an exact number.

While regular decimals are considered "inexact" numbers (i.e. they are assumed to be an approximation), rationals are assumed to be exact. In most cases, the safest thing to do is to consider decimal numbers as inexact to avoid introducing errors in calculations. If you know that the decimal numbers you parse are exact, you can use this option to consider them as exact numbers.

Improvements

LaTeX parser: empty superscripts are now ignored, e.g. 4^{} is interpreted as 4.

0.17.0 2023-10-12

Breaking Changes

The Nothing domain has been renamed to NothingDomain
The Functions, Maybe, Sequence, Dictionary, List and Tuple domain constructors have been renamed to FunctionOf, OptArg, VarArg, DictionaryOf, ListOf and TupleOf, respectively.
Domains no longer require a ["Domain"] expression wrapper, so for example ce.box("Pi").domain returns "TranscendentalNumbers" instead of ["Domain", "TranscendentalNumbers"].
The VarArg domain constructor now indicates the presence of 0 or more arguments, instead of 1 or more arguments.
The MaybeBooleans domain has been dropped. Use ["Union", "Booleans", "NothingDomain"] instead.
The ce.defaultDomain has been dropped. The domain of a symbol is now determined by the context in which it is used, or by the ce.assume() method. In some circumstances, the domain of a symbol can be undefined.

New Features

Symbolic derivatives of expressions can be calculated using the D function. For example, ce.box(["D", ce.parse("x^2 + 3x + 1"), "x"]).evaluate().latex returns "2x + 3".

Improvements

Some frequently used expressions are now available as predefined constants, for example ce.Pi, ce.True and ce.Numbers.
Improved type checking and inference, especially for functions with complicated or non-numeric signatures.

Bugs Fixed

Invoking a function repeatedly would invoke the function in the original scope rather than using a new scope for each invocation.

0.16.0 2023-09-29

Breaking Changes

The methods ce.let() and ce.set() have been renamed to ce.declare() and ce.assign() respectively.
The method ce.assume() requires a predicate.
The signatures of ce.assume() and ce.ask() have been simplified.
The signature of ce.pushScope() has been simplified.
The expr.freeVars property has been renamed to expr.unknowns. It returns the identifiers used in the expression that do not have a value associated with them. The expr.freeVariables property now return the identifiers used in the expression that are defined outside of the local scope and are not arguments of the function, if a function.

New Features

Domain Inference when the domain of a symbol is not set explicitly (for example with ce.declare()), the domain is inferred from the value of the symbol or from the context of its usage.
Added Assume, Identity, Which, Parse, N, Evaluate, Simplify, Domain.
Assignments in LaTeX: x \\coloneq 42 produce ["Assign", "x", 42]
Added ErfInv (inverse error function)
Added Factorial2 (double factorial)

Functions

Functions can now be defined:
- using ce.assign() or ce.declare()
- evaluating LaTeX: (x, y) \mapsto x^2 + y^2
- evaluating MathJSON: ["Function", ["Add", ["Power", "x", 2], ["Power", "y", 2]]], "x", "y"]
Function can be applied using \operatorname{apply} or the operators \rhd and \lhd:
- \operatorname{apply}(f, x)
- f \rhd x
- x \lhd f

See Adding New Definitions and Functions.

Control Structures

Added FixedPoint, Block, If, Loop
Added Break, Continue and Return statements

See Control Structures

Calculus

Added numeric approximation of derivatives, using an 8-th order centered difference approximation, with the ND function.
Added numeric approximation of integrals, using a Monte Carlo method with rebasing for improper integrals, with the NIntegrate function
Added symbolic calculation of derivatives with the D function.

Collections

Added support for collections such as lists, tuples, ranges, etc...

See Collections

Collections can be used to represent various data structures, such as lists, vectors, matrixes and more.

They can be iterated, sliced, filtered, mapped, etc...

["Length", ["List", 19, 23, 5]]
// -> 3

["IsEmpty", ["Range", 1, 10]]
// -> "False"

["Take", ["Linspace", 0, 100, 50], 4]
// -> ["List", 0, 2, 4, 6]

["Map", ["List", 1, 2, 3], ["Function", "x", ["Power", "x", 2]]]
// -> ["List", 1, 4, 9]

["Exclude", ["List", 33, 45, 12, 89, 65], -2, 2]
// -> ["List", 33, 12, 65]


["First", ["List", 33, 45, 12, 89, 65]]
// -> 33

Improvements

The documentation has been significantly rewritten with help from an AI-powered writing assistant.

Issues Resolved

The LaTeX string returned in ["Error"] expression was incorrectly tagged as Latex instead of LatexString.

0.15.0 2023-09-14

Improvements

The ce.serialize() function now takes an optional canonical argument. Set it to false to prevent some transformations that are done to produce more readable LaTeX, but that may not match exactly the MathJSON. For example, by default ce.serialize(["Power", "x", -1]) returns \frac{1}{x} while ce.serialize(["Power", "x", -1], {canonical: false}) returnsx^{-1}.
Improved parsing of delimiters, i.e. \left(, \right], etc...
Added complex functions Real, Imaginary, Arg, Conjugate, AbsArg. See Complex
Added parsing and evaluation of \Re, \Im, \arg, ^\star (Conjugate).
#104 Added the ["ComplexRoots", x, n] function which returns the nthroot of x.
Added parsing and evaluation of statistics functions Mean, Median, StandardDeviation, Variance, Skewness, Kurtosis, Quantile, Quartiles, InterquartileRange, Mode, Count, Erf, Erfc. See Statistics

0.14.0 2023-09-13

Breaking Changes

The entries in the LaTeX syntax dictionary can now have LaTeX triggers (latexTrigger) or triggers based on identifiers (identifierTrigger). The former replaces the trigger property. The latter is new. An entry with a triggerIdentifier of average will match \operatorname{average}, \mathrm{average} and other variants.
The ce.latexOptions and ce.jsonSerializationOptions properties are more robust. They can be modified directly or one of their properties can be modified.

Improvements

Added more functions and symbols supported by expr.compile():
- Factorial postfix operator 5!
- Gamma function \Gamma(2)
- LogGamma function \operatorname{LogGamma}(2)
- Gcd function \operatorname{gcd}(20, 5)
- Lcm function \operatorname{lcm}(20, 5)
- Chop function \operatorname{chop}(0.00000000001)
- Half constant \frac{1}{2}
- 'MachineEpsilon' constant
- GoldenRatio constant
- CatalanConstant constant
- EulerGamma constant \gamma
- Max function \operatorname{max}(1, 2, 3)
- Min function \operatorname{min}(13, 5, 7)
- Relational operators: Less, Greater, LessEqual, GreaterEqual, 'Equal', 'NotEqual'
- Some logical operators and constants: And, Or, Not, True, False
More complex identifiers syntax are recognized, including \mathbin{}, \mathord{}, etc... \operatorname{} is the recommended syntax, though: it will display the identifier in upright font and with the propert spacing, and is properly enclosing. Some commands, such as \mathrm{} are not properly enclosing: two adjacent \mathrm{} command could be merged into one.
Environments are now parsed and serialized correctly.
When parsing LaTeX, function application is properly handled in more cases, including custom functions, e.g. f(x)
When parsing LaTeX, multiple arguments are properly handled, e.g. f(x, y)
Add LaTeX syntax for logical operators:
- And: \land, \operatorname{and} (infix or function)
- Or: \lor, \operatorname{or} (infix or function)
- Not: \lnot, \operatorname{not} (prefix or function)
- Xor: \veebar (infix)
- Nand: \barwedge (infix)
- Nor: ^^^^22BD (infix)
- Implies: \implies (infix)
- Equivalent: \iff (infix)
When a postfix operator is defined in the LaTeX syntax dictionary of the form ^ plus a single token, a definition with braces is added automatically so that both forms will be recognized.
Extended the LaTeX dictionary with:
- floor
- ceil
- round
- sgn
- exp
- abs
- gcd
- lcm
- apply
Properly handle inverse and derivate notations, e.g. \sin^{-1}(x), \sin'(x), \cos''(x), \cos^{(4)}(x)or even\sin^{-1}''(x)`

0.13.0 2023-09-09

New Features

Compilation Some expressions can be compiled to Javascript. This is useful to evaluate an expression many times, for example in a loop. The compiled expression is faster to evaluate than the original expression. To get the compiled expression, use expr.compile(). Read more at Compiling

Issues Resolved and Improvements

Fixed parsing and serialization of extended LaTeX synonyms for e and i.
Fixed serialization of Half.
Fixed serialization of Which
Improved serialization of ["Delimiter"] expressions.

0.12.7 2023-09-08

Improvements

Made customization of the LaTeX dictionary simpler. The ce.latexDictionary property can be used to access and modify the dictionary. The documentation has been updated.

0.12.6 2023-09-08

Breaking Changes

New API for the Parser class.

Improvements and Bux Fixes

The ComputeEngine now exports the bignum() and complex() methods that can be used to create bignum and complex numbers from strings or numbers. The methods isBigNum() and isComplex() have also been added to check if a value is a bignum (Decimal) or complex (Complex) number, for example as returned by expr.numericValue.
#69 \leq was incorrectly parsed as Equals instead of LessEqual
#94 The \exp command was not parsed correctly.
Handle PlusMinus in infix and prefix position, i.e. a\pm b and \pm a.
Improved parsing, serialization
Improved simplification
Improved evaluation of Sum and Product
Support complex identifiers (i.e. non-latin scripts, emojis).
Fixed serialization of mixed numbers.

0.12.1 2022-12-01

Work around unpckg.com issue with libraries using BigInt.

0.12.0 2022-11-27

Breaking Changes

The expr.symbols property return an array of string. Previously it returned an array of BoxedExpression.

Improvements

Rewrote the rational computation engine to use JavaScript bigint instead of Decimal instances. Performance improvements of up to 100x.
expr.freeVars provides the free variables in an expression.
Improved performance of prime factorization of big num by x100.
Added ["RandomExpression"]
Improved accuracy of some operations, for example expr.parse("1e999 + 1").simplify()

Issues Resolved

When ce.numericMode === "auto", square roots of negative numbers would return an expression instead of a complex number.
The formatting of LaTeX numbers when using ce.latexOptions.notation = "engineering" or "scientific" was incorrect.
The trig functions no longer "simplify" to the less simple exponential formulas.
The canonical order of polynomials now orders non-lexicographic terms of degree 1 last, i.e. "ax^2+ bx+ c" instead of "x + ax^2 + bx".
Fixed evaluation of inverse functions
Fixed expr.isLess, expr.isGreater, expr.isLessEqual, expr.isGreaterEqual and ["Min"], ["Max"]

0.11.0 2022-11-18

Breaking Changes

The signature of ce.defineSymbol(), ce.defineFunction() and ce.pushScope() have changed

Improvements

When a constant should be held or substituted with its value can now be more precisely controlled. The hold symbol attribute is now holdUntil and can specify at which stage the substitution should take place.

Issues Resolved

Some constants would return a value as bignum or complex even when the numericMode did not allow it.
Changing the value or domain of a symbol is now correctly taken into account. Changes can be made with ce.assume(), ce.set() or expr.value.
When a symbol does not have a value associated with it, assumptions about it (e.g. "x > 0") are now correctly tracked and reflected.

0.10.0 2022-11-17

Breaking Changes

expr.isLiteral has been removed. Use expr.numericValue !== null and expr.string !== null instead.

Issues Resolved

Calling ce.forget() would not affect expressions that previously referenced the symbol.

Improvements

More accurate calculations of some trig functions when using bignums.
Improved performance when changing a value with ce.set(). Up to 10x faster when evaluating a simple polynomial in a loop.
ce.strict can be set to false to bypass some domain and validity checks.

0.9.0 2022-11-15

Breaking Changes

The head of a number expression is always Number. Use expr.domain to be get more specific info about what kind of number this is.
By default, ce.box() and ce.parse() return a canonical expression. A flag can be used if a non-canonical expression is desired.
The API surface of BoxedExpression has been reduced. The properties machineValue, bignumValue, asFloat, asSmallInteger, asRational etc... have been replaced with a single numericValue property.
parseUnknownSymbol is now parseUnknownIdentifier

Improvements

Support angles in degrees with 30\degree, 30^\circ and \ang{30}.
More accurate error expressions, for example if there is a missing closing delimiter an ["Error", ["ErrorCode", "'expected-closing-delimiter'", "')'"]] is produced.
["Expand"] handles more cases
The trig functions can now have a regular exponent, i.e.\cos^2(x) in addition to -1 for inverse, and a combination of \prime, \doubleprime and ' for derivatives.
ce.assume() handle more expressions and can be used to define new symbols by domain or value.
Better error message when parsing, e.g. \sqrt(2) (instead of \sqrt{2})
Better simplification for square root expressions:
- \sqrt{25x^2} -> 5x
Improved evaluation of ["Power"] expressions, including for negative arguments and non-integer exponents and complex arguments and exponents.
Added Arccot, Arcoth, Arcsch, Arcscc, Arsech and Arccsc
expr.solve() returns result for polynomials of order up to 2.
The pattern.match() function now work correctly for commutative functions, i.e. ce.pattern(['Add', '_a', 'x']).match(ce.parse('x+y')) -> {"_a": "y"}
Added ce.let() and ce.set() to declare and assign values to identifiers.
Preserve exact calculations involving rationals or square root of rationals.
- \sqrt{\frac{49}{25}} -> \frac{7}{5}
Addition and multiplication provide more consistent results for evaluate() and N(). Evaluate returns an exact result when possible.
- EXACT
  - 2 + 5 -> 7
  - 2 + 5/7 -> 19/7
  - 2 + √2 -> 2 + √2
  - 2 + √(5/7) -> 2 + √(5/7)
  - 5/7 + 9/11 -> 118/77
  - 5/7 + √2 -> 5/7 + √2
  - 10/14 + √(18/9) -> 5/7 + √2
  - √2 + √5 -> √2 + √5
  - √2 + √2 -> 2√2
  - sin(2) -> sin(2)
  - sin(π/3) -> √3/2
- APPROXIMATE
  - 2 + 2.1 -> 4.1
  - 2 + √2.1 -> 3.44914
  - 5/7 + √2.1 -> 2.16342
  - sin(2) + √2.1 -> 2.35844
More consistent behavior of the auto numeric mode: calculations are done with bignum and complex in most cases.
JsonSerializationOptions has a new option to specify the numeric precision in the MathJSON serialization.
Shorthand numbers can now be strings if they do not fit in a float-64:

// Before
["Rational", { "num": "1234567890123456789"}, { "num": "2345678901234567889"}]

// Now
["Rational", "1234567890123456789", "2345678901234567889"]

\sum is now correctly parsed and evaluated. This includes creating a local scope with the index and expression value of the sum.

Bugs Fixed

The parsing and evaluation of log functions could produce unexpected results
The \gamma command now correctly maps to ["Gamma"]
Fixed numeric evaluation of the ["Gamma"] function when using bignum
#57 Substituting 0 (i.e. with expr.subs({})) did not work.
#60 Correctly parse multi-char symbols with underscore, i.e. \mathrm{V_a}
Parsing a number with repeating decimals and an exponent would drop the exponent.
Correct calculation of complex square roots
- \sqrt{-49} -> 7i
Calculations were not always performed as bignum in "auto" numeric mode if the precision was less than 15. Now, if the numeric mode is "auto", calculations are done as bignum or complex numbers.
If an identifier contained multiple strings of digits, it would not be rendered to LaTeX correctly, e.g. V20_20.
Correctly return isReal for real numbers

0.8.0 2022-10-02

Breaking Changes

Corrected the implementation of expr.toJSON(), expr.valueOf() and added the esoteric [Symbol.toPrimitive]() method. These are used by JavaScript when interacting with other primitive types. A major change is that expr.toJSON() now returns an Expression as an object literal, and not a string serialization of the Expression.
Changed from "decimal" to "bignum". "Decimal" is a confusing name, since it is used to represent both integers and floating point numbers. Its key characteristic is that it is an arbitrary precision number, aka "bignum". This affects ce.numericMode which now uses bignum instead of decimal', expr.decimalValue->expr.bignumValue, decimalValue()-> bignumValue()`

Bugs Fixed

Numerical evaluation of expressions containing complex numbers when in decimal or auto mode produced incorrect results. Example: e^{i\\pi}

0.7.0 2022-09-30

Breaking Changes

The ce.latexOptions.preserveLatex default value is now false
The first argument of the ["Error"] expression (default value) has been dropped. The first argument is now an error code, either as a string or an ["ErrorCode"] expression.

Features

Much improved LaTeX parser, in particular when parsing invalid LaTeX. The parser now avoids throwing, but will return a partial expression with ["Error"] subexpressions indicating where the problems were.
Implemented new domain computation system (similar to type systems in programming languages)
Added support for multiple signatures per function (ad-hoc polymorphism)
Added FixedPoint, Loop, Product, Sum, Break, Continue, Block, If, Let, Set, Function, Apply, Return
Added Min, Max, Clamp
Parsing of \sum, \prod, \int.
Added parsing of log functions, \lb, \ln, \ln_{10}, \ln_2, etc...
Added expr.subexpressions, expr.getSubexpressions(), expr.errors, expr.symbols, expr.isValid`.
Symbols can now be used to represent functions, i.e. ce.box('Sin').domain correctly returns ["Domain", "Function"].
Correctly handle rational numbers with a numerator or denominator outside the range of a 64-bit float.
Instead of a Missing symbol an ["Error", "'missing'"] expression is used.
Name binding is now done lazily
Correctly handle MathJSON numbers with repeating decimals, e.g. 1.(3).
Correctly evaluate inverse functions, e.g. ce.parse('\\sin^{-1}(.5)).N()
Fixed some LaTeX serialization issues

Read more at Core Reference and [Arithmetic Reference] (https://cortexjs.io/compute-engine/reference/arithmetic/)

Bugs Fixed

#43 If the input of ce.parse() is an empty string, return an empty string for expr.latex or expr.json.latex: that is, ensure verbatim LaTeX round-tripping
Evaluating some functions, such as \arccos would result in a crash
Correctly handle parsing of multi-token decimal markers, e.g. {,}

0.6.0 2022-04-18

Improvements

Parse more cases of tabular environments
Handle simplify and evaluate of inert functions by default
Avoid unnecessary wrapping of functions when serializing LaTeX
Parse arguments of LaTeX commands (e.g. \vec{})
#42 Export static ComputeEngine.getLatexDictionary
Parse multi-character constants and variables, e.g. \mathit{speed} and \mathrm{radius}
Parse/serialize some LaTeX styling commands: \displaystyle, \tiny and more

0.5.0 2022-04-05

Improvements

Correctly parse tabular content (for example in \begin{pmatrix}...\end{pmatrix}
Correctly parse LaTeX groups, i.e. {...}
Ensure constructible trigonometric values are canonical
Correct and simplify evaluation loop for simplify(), evaluate() and N().
#41 Preserve the parsed LaTeX verbatim for top-level expressions
#40 Correctly calculate the synthetic LaTeX metadata for numbers
Only require Node LTS (16.14.2)
Improved documentation, including Dark Mode support

0.4.4

Release Date: 2022-03-27

Improvements

Added option to specify custom LaTeX dictionaries in ComputeEngine constructor
expr.valueOf returns rational numbers as [number, number] when applicable
The non-ESM builds (compute-engine.min.js) now targets vintage JavaScript for improved compatibility with outdated toolchains (e.g. Webpack 4) and environments. The ESM build (compute-engine.min.esm.js) targets evergreen JavaScript (currently ECMAScript 2020).

0.4.3

Release Date: 2022-03-21

Transition Guide from 0.4.2

The API has changed substantially between 0.4.2 and 0.4.3, however adapting code to the new API is very straightforward.

The two major changes are the introduction of the BoxedExpression class and the removal of top level functions.

Boxed Expression

The BoxedExpression class is a immutable box (wrapper) that encapsulates a MathJSON Expression. It provides some member functions that can be used to manipulate the expression, for example expr.simplify() or expr.evaluate().

The boxed expresson itself is immutable. For example, calling expr.simplify() will return a new, simplified, expression, without modifying expr.

To create a "boxed" expression from a "raw" MathJSON expression, use ce.box(). To create a boxed expression from a LaTeX string, use ce.parse().

To access the "raw" MathJSON expression, use the expr.json property. To serialize the expression to LaTeX, use the expr.latex property.

The top level functions such as parse() and evaluate() are now member functions of the ComputeEngine class or the BoxedExpression class.

There are additional member functions to examine the content of a boxed expression. For example, expr.symbol will return null if the expression is not a MathJSON symbol, otherwise it will return the name of the symbol as a string. Similarly, expr.ops return the arguments (operands) of a function, expr.asFloat return null if the expression does not have a numeric value that can be represented by a float, a number otherwise, etc...

Canonical Form

Use expr.canonical to obtain the canonical form of an expression rather than the ce.format() method.

The canonical form is less aggressive in its attempt to simplify than what was performed by ce.format().

The canonical form still accounts for distributive and associative functions, and will collapse some integer constants. However, in some cases it may be necessary to invoke expr.simplify() in order to get the same results as ce.format(expr).

Rational and Division

In addition to machine floating points, arbitrary precision numbers and complex numbers, the Compute Engine now also recognize and process rational numbers.

This is mostly an implementation detail, although you may see ["Rational", 3, 4], for example, in the value of a expr.json property.

If you do not want rational numbers represented in the value of the .json property, you can exclude the Rational function from the serialization of JSON (see below) in which case Divide will be used instead.

Note also that internally (as a result of boxing), Divide is represented as a product of a power with a negative exponent. This makes some pattern detection and simplifications easier. However, when the .json property is accessed, product of powers with a negative exponents are converted to a Divide, unless you have included Divide as an excluded function for serialization.

Similarly, Subtract is converted internally to Add, but may be serialized unless excluded.

Parsing and Serialization Customization

Rather than using a separate instance of the LatexSyntax class to customize the parsing or serialization, use a ComputeEngine instance and its ce.parse() method and the expr.latex property.

Custom dictionaries (to parse/serialize custom LaTeX syntax) can be passed as an argument to the ComputeEngine constructor.

For more advanced customizations, use ce.latexOptions = {...}. For example, to change the formatting options of numbers, how the invisible operator is interpreted, how unknown commands and symbols are interpreted, etc...

Note that there are also now options available for the "serialization" to MathJSON, i.e. when the expr.json property is used. It is possible to control for example if metadata should be included, if shorthand forms are allowed, or whether some functions should be avoided (Divide, Sqrt, Subtract, etc...). These options can be set using ce.jsonSerializationOptions = {...}.

Comparing Expressions

There are more options to compare two expressions.

Previously, match() could be used to check if one expression matched another as a pattern.

If match() returned null, the first expression could not be matched to the second. If it returned an object literal, the two expressions matched.

The top-level match() function is replaced by the expr.match() method. However, there are two other options that may offer better results:

expr.isSame(otherExpr) return true if expr and otherExpr are structurally identical. Structural identity is closely related to the concept of pattern matching, that is ["Add", 1, "x"] and ["Add", "x", 1] are not the same, since the order of the arguments is different. It is useful for example to compare some input to an answer that is expected to have a specific form.
expr.isEqual(otherExpr) return true if expr and otherExpr are mathematically identical. For example ce.parse("1+1").isEqual(ce.parse("2")) will return true. This is useful if the specific structure of the expression is not important.

It is also possible to evaluate a boolean expression with a relational operator, such as Equal:

console.log(ce.box(["Equal", expr, 2]).evaluate().symbol);
// -> "True"

console.log(expr.isEqual(ce.box(2)));
// -> true

Before / After

Before	After
`expr = ["Add", 1, 2]`	`expr = ce.box(["Add", 1, 2])`
`expr = ce.evaluate(expr)`	`expr = expr.evaluate()`
`console.log(expr)`	`console.log(expr.json)`
`expr = new LatexSyntax().parse("x^2+1")`	`expr = ce.parse("x^2+1")`
`new LatexSyntax().serialize(expr)`	`expr.latex`
`ce.simplify(expr)`	`expr.simplify()`
`await ce.evaluate(expr)`	`expr.evaluate()`
`ce.N(expr)`	`expr.N()`
`ce.domain(expr)`	`expr.domain`
`ce.format(expr...)`	`expr.canonical` `expr.simplify()`

0.3.0

Release Date: 2021-06-18

Improvements

In LaTeX, parse \operatorname{foo} as the MathJSON symbol "foo".

Files

CHANGELOG.md

Latest commit

History

CHANGELOG.md

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[Unreleased]

0.26.4 2024-10-17

0.26.3 2024-10-17

0.26.1 2024-10-04

Issues Resolved

New Features and Improvements

0.26.0 2024-10-01

Breaking Changes

New Features and Improvements

Issues Resolved

0.25.1 2024-06-27

Issues Resolved

New Features

0.25.0 2024-06-25

Breaking Changes

New Features

Issues Resolved

0.24.0 2024-02-23

Issues Resolved

0.23.1 2024-01-27

Issues Resolved

0.23.0 2024-01-01

New Features

Issues Resolved

Improvements

0.22.0 2023-11-13

Breaking Changes

Work In Progress

New Features

Improvements

0.21.0 2023-11-02

New Features

Issue Resolved

0.20.2 2023-10-31

Issues Resolved

0.20.1 2023-10-31

Issues Resolved

0.20.0 2023-10-30

Breaking Changes

Issues Resolved

New Features and Improvements

0.19.1 2023-10-26

Issues Resolved

0.19.0 2023-10-25

Breaking Changes

Issues Resolved

New Features

Improvements

0.18.1 2023-10-16

Issues Resolved

Improvements

0.18.0 2023-10-16

New Features

Improvements

0.17.0 2023-10-12

Breaking Changes

New Features

Improvements

Bugs Fixed

0.16.0 2023-09-29

Breaking Changes

New Features

Functions

Control Structures

Calculus

Collections

Improvements

Issues Resolved

0.15.0 2023-09-14

Improvements

0.14.0 2023-09-13

Breaking Changes

Improvements

0.13.0 2023-09-09