Metamath Proof Explorer


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 )