Theorem oteq3

Description: Equality theorem for ordered triples. (Contributed by NM, 3-Apr-2015)

	Ref	Expression
Assertion	oteq3	|- ( A = B -> <. C , D , A >. = <. C , D , B >. )

Proof

Step	Hyp	Ref	Expression
1		opeq2	|- ( A = B -> <. <. C , D >. , A >. = <. <. C , D >. , B >. )
2		df-ot	|- <. C , D , A >. = <. <. C , D >. , A >.
3		df-ot	|- <. C , D , B >. = <. <. C , D >. , B >.
4	1 2 3	3eqtr4g	|- ( A = B -> <. C , D , A >. = <. C , D , B >. )