2013-09-01 17:34:57 +00:00
|
|
|
Set pp::colors false
|
2013-08-18 19:48:02 +00:00
|
|
|
Definition xor (x y : Bool) : Bool := (not x) = y
|
2013-08-20 00:25:15 +00:00
|
|
|
Infixr 50 ⊕ : xor
|
2013-08-18 19:48:02 +00:00
|
|
|
Show xor true false
|
|
|
|
Eval xor true true
|
|
|
|
Eval xor true false
|
|
|
|
Variable a : Bool
|
|
|
|
Show a ⊕ a ⊕ a
|
2013-08-30 22:56:04 +00:00
|
|
|
Check Subst::explicit
|
2013-08-18 19:48:02 +00:00
|
|
|
Theorem EM2 (a : Bool) : a \/ (not a) :=
|
|
|
|
Case (fun x : Bool, x \/ (not x)) Trivial Trivial a
|
|
|
|
Check EM2
|
|
|
|
Check EM2 a
|