cons :: a → c → c
dropWhile :: (a → b) → c → c
if :: b → c → c → c
nil :: c
takeWhile :: (a → b) → c → c
true :: b
if(true, X, Y) → X
if(true, U, V) → V
takeWhile(I, nil) → nil
takeWhile(J, cons(X1, Y1)) → if(J(X1), cons(X1, takeWhile(J, Y1)), nil)
dropWhile(G1, nil) → nil
dropWhile(H1, cons(W1, P1)) → if(H1(W1), dropWhile(H1, P1), cons(W1, P1))