Theorem neeqtrd 2368

Description: Substitution of equal classes into an inequality. (Contributed by NM, 4-Jul-2012.)

Hypotheses

Ref	Expression
neeqtrd.1	|- ( ph -> A =/= B )
neeqtrd.2	|- ( ph -> B = C )

Assertion

Ref	Expression
neeqtrd	|- ( ph -> A =/= C )

Proof of Theorem neeqtrd

Step	Hyp	Ref	Expression
1		neeqtrd.1	. 2 |- ( ph -> A =/= B )
2		neeqtrd.2	. . 3 |- ( ph -> B = C )
3	2	neeq2d 2359	. 2 |- ( ph -> ( A =/= B <-> A =/= C ) )
4	1, 3	mpbid 146	1 |- ( ph -> A =/= C )

Syntax hints:   -> wi 4   = wceq 1348   =/= wne 2340

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 609  ax-in2 610  ax-5 1440  ax-gen 1442  ax-4 1503  ax-17 1519  ax-ext 2152

This theorem depends on definitions:  df-bi 116  df-cleq 2163  df-ne 2341

This theorem is referenced by:  neeqtrrd  2370  xaddass2  9827  modsumfzodifsn  10352