Metamath Proof Explorer


Theorem eqtr3i

Description: An equality transitivity inference. (Contributed by NM, 6-May-1994)

Ref Expression
Hypotheses eqtr3i.1
|- A = B
eqtr3i.2
|- A = C
Assertion eqtr3i
|- B = C

Proof

Step Hyp Ref Expression
1 eqtr3i.1
 |-  A = B
2 eqtr3i.2
 |-  A = C
3 1 eqcomi
 |-  B = A
4 3 2 eqtri
 |-  B = C