Metamath Proof Explorer


Theorem tpeq123d

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

Ref Expression
Hypotheses tpeq1d.1 φ A = B
tpeq123d.2 φ C = D
tpeq123d.3 φ E = F
Assertion tpeq123d φ A C E = B D F

Proof

Step Hyp Ref Expression
1 tpeq1d.1 φ A = B
2 tpeq123d.2 φ C = D
3 tpeq123d.3 φ E = F
4 1 tpeq1d φ A C E = B C E
5 2 tpeq2d φ B C E = B D E
6 3 tpeq3d φ B D E = B D F
7 4 5 6 3eqtrd φ A C E = B D F