Theorem rexv 2572

Description: An existential quantifier restricted to the universe is unrestricted. (Contributed by NM, 26-Mar-2004.)

Assertion

Ref	Expression
rexv	|- ( E. x e. _V ph <-> E. x ph )

Proof of Theorem rexv

Step	Hyp	Ref	Expression
1		df-rex 2312	. 2 |- ( E. x e. _V ph <-> E. x ( x e. _V /\ ph ) )
2		vex 2560	. . . 4 |- x e. _V
3	2	biantrur 287	. . 3 |- ( ph <-> ( x e. _V /\ ph ) )
4	3	exbii 1496	. 2 |- ( E. x ph <-> E. x ( x e. _V /\ ph ) )
5	1, 4	bitr4i 176	1 |- ( E. x e. _V ph <-> E. x ph )

Syntax hints:   /\ wa 97   <-> wb 98   E.wex 1381   e. wcel 1393   E.wrex 2307   _Vcvv 2557

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-5 1336  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-4 1400  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-rex 2312  df-v 2559

This theorem is referenced by:  rexcom4  2577  spesbc  2843  dfco2  4820  dfco2a  4821