LAMBDA JS
A useful reference of lambda calculus using JavaScript semantics

// Propositional logic implemenation
const True  = a => b => a;
const False = a => b => b;
const If    = x => x;
const Not   = a => a(False)(True);
const And   = a => b => a(True)(False)(b(True)(False))(False);
const Or    = a => b => a(True)(b(True)(False));
const Xor   = a => b => And(Or(a)(b))(Not(And(a)(b)));

// SKI calculus implementation
const S = x => y => z => x(z)(y(z));
const K = x => y => x;
const I = x => x;

// Iota combinator calculus
const i = x => x(S)(K);

// Lists
const First  = True;
const Second = False;
const Nil    = False;
const Pair   = P = fst  => snd => func => func(fst)(snd);
const Map    = M = func => fst => snd  => Pair(func(fst))(snd(Map(func)));
const Push   = p => el => P(el)(P(p(First))(p(Second)));

// Arithmetic
const Add = m => n => f => x => m(f)(n(f)(x));
const Mul = m => n => f => m(n(f));

const _0  = False;
const _1  = f => x => f(x);
const _2  = Add(_1)(_1);
const _3  = Add(_1)(_2);
const _4  = Mul(_2)(_2);
const _5  = Add(_2)(_3);
const _6  = Add(_2)(_4);
const _7  = Add(_1)(_6);
const _8  = Mul(_2)(_4);
const _9  = Add(_1)(_8);
const _10 = Mul(_2)(_5);

// Binary
const Byte = _8(P(_0))(Nil);