* :: a → a → a
1 :: a
cons :: c → d → d
false :: b
filter :: (c → b) → d → d
filter2 :: b → (c → b) → c → d → d
i :: a → a
map :: (c → c) → d → d
nil :: d
true :: b
*(1, X) → X
*(Y, 1) → Y
*(i(U), U) → 1
*(V, i(V)) → 1
*(i(W), *(W, P)) → P
*(X1, *(i(X1), Y1)) → Y1
i(1) → 1
i(i(U1)) → U1
map(H1, nil) → nil
map(I1, cons(P1, X2)) → cons(I1(P1), map(I1, X2))
filter(Z2, nil) → nil
filter(G2, cons(V2, W2)) → filter2(G2(V2), G2, V2, W2)
filter2(true, J2, X3, Y3) → cons(X3, filter(J2, Y3))
filter2(false, G3, V3, W3) → filter(G3, W3)