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 ∈ ℝ → A + 0 - ℝ A = 0

Proof

Step Hyp Ref Expression
1 eqid ⊢ 0 - ℝ A = 0 - ℝ A
2 rernegcl ⊢ A ∈ ℝ → 0 - ℝ A ∈ ℝ
3 renegadd ⊢ A ∈ ℝ ∧ 0 - ℝ A ∈ ℝ → 0 - ℝ A = 0 - ℝ A ↔ A + 0 - ℝ A = 0
4 2 3 mpdan ⊢ A ∈ ℝ → 0 - ℝ A = 0 - ℝ A ↔ A + 0 - ℝ A = 0
5 1 4 mpbii ⊢ A ∈ ℝ → A + 0 - ℝ A = 0