Theorem nelir

Description: Inference associated with df-nel . (Contributed by BJ, 7-Jul-2018)

	Ref	Expression
Hypothesis	nelir.1	|- -. A e. B
Assertion	nelir	|- A e/ B

Proof

Step	Hyp	Ref	Expression
1		nelir.1	|- -. A e. B
2		df-nel	|- ( A e/ B <-> -. A e. B )
3	1 2	mpbir	|- A e/ B