combinator.scala

@ def id[A](x: A): A = x
defined function id

@ def k[A, B](x: A, y: B): A = x 
defined function k

@ def a[A, B](f: A => B, x: A): B = f(x) 
defined function a

@ a((x: Int) => x + 1, 1) 
res3: Int = 2

@ def t[A, B](x: A, f: A => B): B = f(x) 
defined function t

@ def w[A, B](f: A => A => B, x: A): B = f(x)(x) 
defined function w

@ def c[A, B, C](f: A => B => C, y: B, x: A): C = f(x)(y) 
defined function c

@ def b[A, B, C](f: B => C, g: A => B, x: A): C = f(g(x)) 
defined function b

@ def s[A, B, C](f: A => B => C, g: A => B, x: A): C = f(x)(g(x)) 
defined function s

@ def p[A, B, C](f: B => B => C, g: A => B, x: A, y: A): C = f(g(x))(g(y)) 
defined function p

@ def y(f: ???, g: ???, x: ???): ??? = f((x: ???) => g(g)(x))