Metamath Proof Explorer


Theorem readdid1

Description: Real number version of addid1 , without ax-mulcom . (Contributed by SN, 23-Jan-2024)

Ref Expression
Assertion readdid1 A A + 0 = A

Proof

Step Hyp Ref Expression
1 resubid A A - A = 0
2 id A A
3 elre0re A 0
4 2 2 3 resubaddd A A - A = 0 A + 0 = A
5 1 4 mpbid A A + 0 = A