Theorem xornbi 1397

Description: A consequence of exclusive or. For decidable propositions this is an equivalence, as seen at xornbidc 1402. (Contributed by Jim Kingdon, 10-Mar-2018.)

Assertion

Ref	Expression
xornbi	|- ( ( ph \/_ ps ) -> -. ( ph <-> ps ) )

Proof of Theorem xornbi

Step	Hyp	Ref	Expression
1		xorbin 1395	. 2 |- ( ( ph \/_ ps ) -> ( ph <-> -. ps ) )
2		pm5.18im 1396	. . 3 |- ( ( ph <-> ps ) -> -. ( ph <-> -. ps ) )
3	2	con2i 628	. 2 |- ( ( ph <-> -. ps ) -> -. ( ph <-> ps ) )
4	1, 3	syl 14	1 |- ( ( ph \/_ ps ) -> -. ( ph <-> ps ) )

Syntax hints:   -. wn 3   -> wi 4   <-> wb 105   \/_ wxo 1386

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 615  ax-in2 616  ax-io 710

This theorem depends on definitions:  df-bi 117  df-xor 1387

This theorem is referenced by: (None)