ski_combinator.stringlang

/* The Calculus */
I = fun(x) { x };
K = fun(x) { fun(y) { x } };
S = fun(x) { fun(y) { fun(z) { x(z)(y(z)) } } };

/* Booleans */
T = K;
F = S(K);

/* I am unsure how safe this comparison of lambdas is */
bool_str = fun(b) { b == T };

/* Boolean operators */
NOT = S(S(I)(K(F)))(K(T));
OR = S(I)(K(T));
AND = S(S)(K(K(F)));

other_k = S(K)(S)(K);

I("Identity") + "\n" +
K("Always Me")("Never Me") + "\n" +
other_k("also Always Me")("also Never Me") + "\n\n" +

"NOT T = " + bool_str(NOT(T)) + ", NOT F = " + bool_str(NOT(F)) + "\n" +
"T AND F = " + bool_str(AND(T)(F)) + ", T AND T = " + bool_str(AND(T)(T)) + "\n" +
"F OR T = " + bool_str(OR(F)(T)) + ", F OR F = " + bool_str(OR(F)(F))