Theorem ifex 4606

Description: Existence of the conditional operator (inference form). (Contributed by NM, 2-Sep-2004.)

Hypotheses

Ref	Expression
ifex.1	|- A e. _V
ifex.2	|- B e. _V

Assertion

Ref	Expression
ifex	|- if ( ph , A , B ) e. _V

Proof of Theorem ifex

Step	Hyp	Ref	Expression
1		ifex.1	. 2 |- A e. _V
2		ifex.2	. 2 |- B e. _V
3		ifexg 4605	. 2 |- ( ( A e. _V /\ B e. _V ) -> if ( ph , A , B ) e. _V )
4	1, 2, 3	mp2an 426	1 |- if ( ph , A , B ) e. _V

Syntax hints:   e. wcel 2203   _Vcvv 2812   ifcif 3619

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-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2205  ax-14 2206  ax-ext 2214  ax-sep 4227  ax-pr 4321  ax-un 4553

This theorem depends on definitions:  df-bi 117  df-tru 1401  df-nf 1510  df-sb 1812  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-rex 2526  df-rab 2529  df-v 2814  df-un 3214  df-in 3216  df-ss 3223  df-if 3620  df-pw 3670  df-sn 3694  df-pr 3695  df-uni 3914

This theorem is referenced by:  elply2  15587  pw1map  16756  nnnninfex  16787