Theorem ceqsalv 2782

Description: A representation of explicit substitution of a class for a variable, inferred from an implicit substitution hypothesis. (Contributed by NM, 18-Aug-1993.)

Hypotheses

Ref	Expression
ceqsalv.1	|- A e. _V
ceqsalv.2	|- ( x = A -> ( ph <-> ps ) )

Assertion

Ref	Expression
ceqsalv	|- ( A. x ( x = A -> ph ) <-> ps )

Distinct variable groups:   x, A   ps, x

Allowed substitution hint:   ph( x)

Proof of Theorem ceqsalv

Step	Hyp	Ref	Expression
1		nfv 1539	. 2 |- F/ x ps
2		ceqsalv.1	. 2 |- A e. _V
3		ceqsalv.2	. 2 |- ( x = A -> ( ph <-> ps ) )
4	1, 2, 3	ceqsal 2781	1 |- ( A. x ( x = A -> ph ) <-> ps )

Syntax hints:   -> wi 4   <-> wb 105   A.wal 1362   = wceq 1364   e. wcel 2160   _Vcvv 2752

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-5 1458  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-ext 2171

This theorem depends on definitions:  df-bi 117  df-nf 1472  df-sb 1774  df-clab 2176  df-cleq 2182  df-clel 2185  df-v 2754

This theorem is referenced by:  gencbval  2800  clel2  2885  clel4  2888  reu8  2948  raliunxp  4783  fv3  5553