Theorem altopeq1

Description: Equality for alternate ordered pairs. (Contributed by Scott Fenton, 22-Mar-2012)

	Ref	Expression
Assertion	altopeq1	$$⊢A=B\to ⟪A,C⟫=⟪B,C⟫$$

Proof

Step	Hyp	Ref	Expression
1		eqid	$$⊢C=C$$
2		altopeq12	$$⊢\left(A=B\wedge C=C\right)\to ⟪A,C⟫=⟪B,C⟫$$
3	1 2	mpan2	$$⊢A=B\to ⟪A,C⟫=⟪B,C⟫$$