Metamath Proof Explorer


Theorem ax12ev2c

Description: A commuted form of ax12ev2 . (Contributed by BTernaryTau, 8-Sep-2026)

Ref Expression
Assertion ax12ev2c
|- ( x = y -> ( E. y ( x = y /\ ph ) -> ph ) )

Proof

Step Hyp Ref Expression
1 equcomi
 |-  ( x = y -> y = x )
2 1 anim1i
 |-  ( ( x = y /\ ph ) -> ( y = x /\ ph ) )
3 2 eximi
 |-  ( E. y ( x = y /\ ph ) -> E. y ( y = x /\ ph ) )
4 ax12ev2
 |-  ( E. y ( y = x /\ ph ) -> ( y = x -> ph ) )
5 3 1 4 syl2imc
 |-  ( x = y -> ( E. y ( x = y /\ ph ) -> ph ) )