Theorem abeq1i 2278

Description: Equality of a class variable and a class abstraction (inference form). (Contributed by NM, 31-Jul-1994.)

Hypothesis

Ref	Expression
abeqri.1	|- { x | ph } = A

Assertion

Ref	Expression
abeq1i	|- ( ph <-> x e. A )

Proof of Theorem abeq1i

Step	Hyp	Ref	Expression
1		abid 2153	. 2 |- ( x e. { x | ph } <-> ph )
2		abeqri.1	. . 3 |- { x | ph } = A
3	2	eleq2i 2233	. 2 |- ( x e. { x | ph } <-> x e. A )
4	1, 3	bitr3i 185	1 |- ( ph <-> x e. A )

Syntax hints:   <-> wb 104   = wceq 1343   e. wcel 2136   {cab 2151

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-5 1435  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-ext 2147

This theorem depends on definitions:  df-bi 116  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161

This theorem is referenced by: (None)