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