diff --git a/scala3/src/main/scala/examples/Main.scala b/scala3/src/main/scala/examples/Main.scala
deleted file mode 100644
index 70dede4..0000000
--- a/scala3/src/main/scala/examples/Main.scala
+++ /dev/null
@@ -1,15 +0,0 @@
-package examples
-
-import zio.{ZIOAppDefault, Task, Console}
-import zio.Console.ConsoleLive
-
-object Main extends ZIOAppDefault:
-
-  def app(c: Console): Task[Unit] =
-    for
-      _    <- c.printLine("What is your name?")
-      name <- c.readLine
-      _    <- c.printLine(s"Hello $name!")
-    yield ()
-
-  def run = app(ConsoleLive)
diff --git a/scala3/src/main/scala/examples/adts.scala b/scala3/src/main/scala/examples/adts.scala
index 67c1480..0695948 100644
--- a/scala3/src/main/scala/examples/adts.scala
+++ b/scala3/src/main/scala/examples/adts.scala
@@ -12,7 +12,7 @@ object adts:
   case object False extends Bool
   
   final case class RgbPair(snd: Bool, fst: Rgb)
-  
+
   def idRgb(theArg: Rgb): Rgb = theArg
   
-  def and0(rgbArg: Rgb, rgbPairArg: RgbPair): RgbPair = rgbPairArg
+  def constRgbPair(rgbArg: Rgb, rgbPairArg: RgbPair): RgbPair = rgbPairArg
diff --git a/scala3/src/test/scala/examples/MainSpec.scala b/scala3/src/test/scala/examples/MainSpec.scala
deleted file mode 100644
index 78b3203..0000000
--- a/scala3/src/test/scala/examples/MainSpec.scala
+++ /dev/null
@@ -1,13 +0,0 @@
-package examples
-
-import zio.test.Assertion.equalTo
-import zio.test.junit.JUnitRunnableSpec
-import zio.test.{ assert, suite, test }
-
-object MainSpec extends JUnitRunnableSpec:
-
-  def spec = suite("Test environment")(
-    test("expect call with input satisfying assertion") {
-      assert(40 + 2)(equalTo(42))
-    }
-  )
diff --git a/scala3/src/test/scala/examples/RgbSpec.scala b/scala3/src/test/scala/examples/RgbSpec.scala
new file mode 100644
index 0000000..199fbfa
--- /dev/null
+++ b/scala3/src/test/scala/examples/RgbSpec.scala
@@ -0,0 +1,24 @@
+package examples
+
+import zio.test.Assertion.equalTo
+import zio.test.junit.JUnitRunnableSpec
+import zio.test.{ assert, suite, test }
+
+import examples.adts.{ Rgb, Red, Green, Blue, idRgb }
+import examples.adts.{ RgbPair, constRgbPair }
+import examples.adts.{ Bool, True, False }
+
+object RgbSpec extends JUnitRunnableSpec:
+
+  def spec = suite("Test Rgb")(
+    test("identity on Rgb") {
+      assert(idRgb(Red))(equalTo(Red))
+      assert(idRgb(Green))(equalTo(Green))
+      assert(idRgb(Blue))(equalTo(Blue))
+    },
+    test ("const on RgbPair") {
+      assert( constRgbPair(Red,   RgbPair(True, Blue) ) )(equalTo( RgbPair(True, Blue) ))
+      assert( constRgbPair(Green, RgbPair(False, Red) ) )(equalTo( RgbPair(False, Red) ))
+      assert( constRgbPair(Blue,  RgbPair(True, Blue) ) )(equalTo( RgbPair(True, Blue) ))
+    }
+  )