enum begin
    False = -1,
    Maybe,
    True
end

local Chrs <const> = {"F", "M", "T"}

class trit
    public v

    function __construct(v)
        assert(v == False or v == Maybe or v == True, "Invalid argument.")
        self.v = v
    end

    function __bnot()      return new trit(-self.v) end

    function __band(other) return (self.v < other.v)  ? (self) : other end

    function __bor(other)  return (self.v > other.v)  ? (self) : other end

    function __shr(other)  return (-self.v > other.v) ? (~self) : other end

    function   eqv(other)  return new trit(self.v * other.v) end

    function __tostring()  return Chrs[self.v + 2] end
end

local trits = {new trit(True), new trit(Maybe), new trit(False)}

print("not")
print("-------")
for trits as t do print($" {t} | {~t}") end

print("\nand | T  M  F")
print("-------------")
for trits as t do
    io.write($" {t}  | ")
    for trits as u do io.write($"{tostring(t & u)}  ") end
    print()
end

print("\nor  | T  M  F")
print("-------------")
for trits as t do
    io.write($" {t}  | ")
    for trits as u do io.write($"{tostring(t | u)}  ") end
    print()
end

print("\nimp | T  M  F")
print("-------------")
for trits as t do
    io.write($" {t}  | ")
    for trits as u do io.write($"{tostring(t >> u)}  ") end
    print()
end

print("\neqv | T  M  F")
print("-------------")
for trits as t do
    io.write($" {t}  | ")
    for trits as u do io.write($"{tostring(t:eqv(u))}  ") end
    print()
end