Metamath Proof Explorer


Theorem tpeq123d

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

Ref Expression
Hypotheses tpeq1d.1
|- ( ph -> A = B )
tpeq123d.2
|- ( ph -> C = D )
tpeq123d.3
|- ( ph -> E = F )
Assertion tpeq123d
|- ( ph -> { A , C , E } = { B , D , F } )

Proof

Step Hyp Ref Expression
1 tpeq1d.1
 |-  ( ph -> A = B )
2 tpeq123d.2
 |-  ( ph -> C = D )
3 tpeq123d.3
 |-  ( ph -> E = F )
4 1 tpeq1d
 |-  ( ph -> { A , C , E } = { B , C , E } )
5 2 tpeq2d
 |-  ( ph -> { B , C , E } = { B , D , E } )
6 3 tpeq3d
 |-  ( ph -> { B , D , E } = { B , D , F } )
7 4 5 6 3eqtrd
 |-  ( ph -> { A , C , E } = { B , D , F } )