Theorem bnj1113

Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

	Ref	Expression
Hypothesis	bnj1113.1	$$⊢A=B\to C=D$$
Assertion	bnj1113	$$⊢A=B\to \bigcup _{x\in C}E=\bigcup _{x\in D}E$$

Proof

Step	Hyp	Ref	Expression
1		bnj1113.1	$$⊢A=B\to C=D$$
2	1	iuneq1d	$$⊢A=B\to \bigcup _{x\in C}E=\bigcup _{x\in D}E$$