Metamath Proof Explorer


Theorem renegid

Description: Addition of a real number and its negative. (Contributed by Steven Nguyen, 7-Jan-2023)

Ref Expression
Assertion renegid A A + 0 - A = 0

Proof

Step Hyp Ref Expression
1 eqid 0 - A = 0 - A
2 rernegcl A 0 - A
3 renegadd A 0 - A 0 - A = 0 - A A + 0 - A = 0
4 2 3 mpdan A 0 - A = 0 - A A + 0 - A = 0
5 1 4 mpbii A A + 0 - A = 0