Theorem cbvexv 2003

Description: Rule used to change bound variables, using implicit substitution. (Contributed by NM, 5-Aug-1993.)

Hypothesis

Ref	Expression
cbvalv.1	|- (x = y -> (ph <-> ps))

Assertion

Ref	Expression
cbvexv	|- (E.xph <-> E.yps)

Distinct variable groups:   ph,y   ps,x

Allowed substitution hints:   ph(x)   ps(y)

Proof of Theorem cbvexv

Step	Hyp	Ref	Expression
1		nfv 1619	. 2 |- F/yph
2		nfv 1619	. 2 |- F/xps
3		cbvalv.1	. 2 |- (x = y -> (ph <-> ps))
4	1, 2, 3	cbvex 1985	1 |- (E.xph <-> E.yps)

Syntax hints:   -> wi 4   <-> wb 176  E.wex 1541

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925

This theorem depends on definitions:  df-bi 177  df-an 360  df-tru 1319  df-ex 1542  df-nf 1545

This theorem is referenced by:  eujust  2206  euind  3024  reuind  3040  cbvopab2v  4637  fv3  5342