Theorem iftruei 3337

Description: Inference associated with iftrue 3336. (Contributed by BJ, 7-Oct-2018.)

Hypothesis

Ref	Expression
iftruei.1	|- ph

Assertion

Ref	Expression
iftruei	|- if ( ph , A , B ) = A

Proof of Theorem iftruei

Step	Hyp	Ref	Expression
1		iftruei.1	. 2 |- ph
2		iftrue 3336	. 2 |- ( ph -> if ( ph , A , B ) = A )
3	1, 2	ax-mp 7	1 |- if ( ph , A , B ) = A

Syntax hints:   = wceq 1243   ifcif 3331

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-in2 545  ax-io 630  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-11 1397  ax-4 1400  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-if 3332

This theorem is referenced by:  xnegpnf  8741  xnegmnf  8742  exp0  9259