Metamath Proof Explorer


Theorem scottab

Description: Value of the Scott operation at a class abstraction. (Contributed by Rohan Ridenour, 14-Aug-2023)

Ref Expression
Hypothesis scottab.1
|- ( x = y -> ( ph <-> ps ) )
Assertion scottab
|- Scott { x | ph } = { x | ( ph /\ A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) ) }

Proof

Step Hyp Ref Expression
1 scottab.1
 |-  ( x = y -> ( ph <-> ps ) )
2 nfv
 |-  F/ x ps
3 2 1 scottabf
 |-  Scott { x | ph } = { x | ( ph /\ A. y ( ps -> ( rank ` x ) C_ ( rank ` y ) ) ) }