def XOR(x1, x2): s1 = OR(x1, x2) s2 = NAND(x1, x2) y = AND(s1, s2) if (y <= 0): return 0 else: return 1
def XOR(x1, x2): s1 = NAND(x1, x2) s2 = OR(x1, x2) y = AND(s1, s2) return y