Add more operators

[Specy]

Maybe i should add the possibility to create different kinds of operators like the dot product, square root, etc, it might be useful for things like this, those cannot be linearized, so maybe add it for other kinds of non linearized problems? perhaps i could, other than linear problems, allow the resolution of any kind of problem by using the recursive nature of the expression language and a context that solves to numeric values.

Alternatively, maybe i could do some pre processing for known values, like the dot product over an array, or the square root of a number