Theorem pm2.21ddne 2389

Description: A contradiction implies anything. Equality/inequality deduction form. (Contributed by David Moews, 28-Feb-2017.)

Hypotheses

Ref	Expression
pm2.21ddne.1	|- ( ph -> A = B )
pm2.21ddne.2	|- ( ph -> A =/= B )

Assertion

Ref	Expression
pm2.21ddne	|- ( ph -> ps )

Proof of Theorem pm2.21ddne

Step	Hyp	Ref	Expression
1		pm2.21ddne.1	. 2 |- ( ph -> A = B )
2		pm2.21ddne.2	. . 3 |- ( ph -> A =/= B )
3	2	neneqd 2327	. 2 |- ( ph -> -. A = B )
4	1, 3	pm2.21dd 609	1 |- ( ph -> ps )

Syntax hints:   -> wi 4   = wceq 1331   =/= wne 2306

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-in2 604

This theorem depends on definitions:  df-bi 116  df-ne 2307

This theorem is referenced by:  npnflt  9591  nmnfgt  9594  xlt2add  9656  xrbdtri  11038  divalglemex  11608  divalg  11610  znege1  11845  ennnfonelemex  11916