Theorem equncom

Description: If a class equals the union of two other classes, then it equals the union of those two classes commuted. equncom was automatically derived from equncomVD using the tools program translate__without__overwriting.cmd and minimizing. (Contributed by Alan Sare, 18-Feb-2012)

	Ref	Expression
Assertion	equncom	$$⊢A=B\cup C\leftrightarrow A=C\cup B$$

Proof

Step	Hyp	Ref	Expression
1		uncom	$$⊢B\cup C=C\cup B$$
2	1	eqeq2i	$$⊢A=B\cup C\leftrightarrow A=C\cup B$$