Metamath Proof Explorer


Theorem cbvoprab3v

Description: Rule used to change the third bound variable in an operation abstraction, using implicit substitution. (Contributed by NM, 8-Oct-2004) (Revised by David Abernethy, 19-Jun-2012)

Ref Expression
Hypothesis cbvoprab3v.1
|- ( z = w -> ( ph <-> ps ) )
Assertion cbvoprab3v
|- { <. <. x , y >. , z >. | ph } = { <. <. x , y >. , w >. | ps }

Proof

Step Hyp Ref Expression
1 cbvoprab3v.1
 |-  ( z = w -> ( ph <-> ps ) )
2 nfv
 |-  F/ w ph
3 nfv
 |-  F/ z ps
4 2 3 1 cbvoprab3
 |-  { <. <. x , y >. , z >. | ph } = { <. <. x , y >. , w >. | ps }