Metamath Proof Explorer


Theorem eqtr2i

Description: An equality transitivity inference. (Contributed by NM, 21-Feb-1995)

Ref Expression
Hypotheses eqtr2i.1 A = B
eqtr2i.2 B = C
Assertion eqtr2i C = A

Proof

Step Hyp Ref Expression
1 eqtr2i.1 A = B
2 eqtr2i.2 B = C
3 1 2 eqtri A = C
4 3 eqcomi C = A