Theorem xaddid2d

Description: 0 is a left identity for extended real addition. (Contributed by Glauco Siliprandi, 17-Aug-2020)

	Ref	Expression
Hypothesis	xaddid2d.1	|- ( ph -> A e. RR* )
Assertion	xaddid2d	|- ( ph -> ( 0 +e A ) = A )

Proof

Step	Hyp	Ref	Expression
1		xaddid2d.1	|- ( ph -> A e. RR* )
2		xaddid2	|- ( A e. RR* -> ( 0 +e A ) = A )
3	1 2	syl	|- ( ph -> ( 0 +e A ) = A )