Metamath Proof Explorer


Theorem sylan9eqr

Description: An equality transitivity deduction. (Contributed by NM, 8-May-1994)

Ref Expression
Hypotheses sylan9eqr.1 φA=B
sylan9eqr.2 ψB=C
Assertion sylan9eqr ψφA=C

Proof

Step Hyp Ref Expression
1 sylan9eqr.1 φA=B
2 sylan9eqr.2 ψB=C
3 1 2 sylan9eq φψA=C
4 3 ancoms ψφA=C