Metamath Proof Explorer


Theorem eqeltrrdi

Description: A membership and equality inference. (Contributed by NM, 4-Jan-2006)

Ref Expression
Hypotheses eqeltrrdi.1
|- ( ph -> B = A )
eqeltrrdi.2
|- B e. C
Assertion eqeltrrdi
|- ( ph -> A e. C )

Proof

Step Hyp Ref Expression
1 eqeltrrdi.1
 |-  ( ph -> B = A )
2 eqeltrrdi.2
 |-  B e. C
3 1 eqcomd
 |-  ( ph -> A = B )
4 3 2 eqeltrdi
 |-  ( ph -> A e. C )