Metamath Proof Explorer


Theorem tpeq1d

Description: Equality theorem for unordered triples. (Contributed by NM, 22-Jun-2014)

Ref Expression
Hypothesis tpeq1d.1 φ A = B
Assertion tpeq1d φ A C D = B C D

Proof

Step Hyp Ref Expression
1 tpeq1d.1 φ A = B
2 tpeq1 A = B A C D = B C D
3 1 2 syl φ A C D = B C D