Metamath Proof Explorer


Theorem bj-gabss

Description: Inclusion of generalized class abstractions. (Contributed by BJ, 4-Oct-2024)

Ref Expression
Assertion bj-gabss
|- ( A. x ( A = B /\ ( ph -> ps ) ) -> {{ A | x | ph }} C_ {{ B | x | ps }} )

Proof

Step Hyp Ref Expression
1 eqeq1
 |-  ( A = B -> ( A = y <-> B = y ) )
2 1 biimpd
 |-  ( A = B -> ( A = y -> B = y ) )
3 2 adantr
 |-  ( ( A = B /\ ( ph -> ps ) ) -> ( A = y -> B = y ) )
4 simpr
 |-  ( ( A = B /\ ( ph -> ps ) ) -> ( ph -> ps ) )
5 3 4 anim12d
 |-  ( ( A = B /\ ( ph -> ps ) ) -> ( ( A = y /\ ph ) -> ( B = y /\ ps ) ) )
6 5 aleximi
 |-  ( A. x ( A = B /\ ( ph -> ps ) ) -> ( E. x ( A = y /\ ph ) -> E. x ( B = y /\ ps ) ) )
7 6 alrimiv
 |-  ( A. x ( A = B /\ ( ph -> ps ) ) -> A. y ( E. x ( A = y /\ ph ) -> E. x ( B = y /\ ps ) ) )
8 ss2ab
 |-  ( { y | E. x ( A = y /\ ph ) } C_ { y | E. x ( B = y /\ ps ) } <-> A. y ( E. x ( A = y /\ ph ) -> E. x ( B = y /\ ps ) ) )
9 7 8 sylibr
 |-  ( A. x ( A = B /\ ( ph -> ps ) ) -> { y | E. x ( A = y /\ ph ) } C_ { y | E. x ( B = y /\ ps ) } )
10 df-bj-gab
 |-  {{ A | x | ph }} = { y | E. x ( A = y /\ ph ) }
11 df-bj-gab
 |-  {{ B | x | ps }} = { y | E. x ( B = y /\ ps ) }
12 9 10 11 3sstr4g
 |-  ( A. x ( A = B /\ ( ph -> ps ) ) -> {{ A | x | ph }} C_ {{ B | x | ps }} )