Metamath Proof Explorer


Theorem cbvoprab12v

Description: Rule used to change first two bound variables in an operation abstraction, using implicit substitution. (Contributed by NM, 8-Oct-2004)

Ref Expression
Hypothesis cbvoprab12v.1
|- ( ( x = w /\ y = v ) -> ( ph <-> ps ) )
Assertion cbvoprab12v
|- { <. <. x , y >. , z >. | ph } = { <. <. w , v >. , z >. | ps }

Proof

Step Hyp Ref Expression
1 cbvoprab12v.1
 |-  ( ( x = w /\ y = v ) -> ( ph <-> ps ) )
2 nfv
 |-  F/ w ph
3 nfv
 |-  F/ v ph
4 nfv
 |-  F/ x ps
5 nfv
 |-  F/ y ps
6 2 3 4 5 1 cbvoprab12
 |-  { <. <. x , y >. , z >. | ph } = { <. <. w , v >. , z >. | ps }