Metamath Proof Explorer


Theorem sn-redividd

Description: A number divided by itself is 1. (Contributed by SN, 2-Apr-2026)

Ref Expression
Hypotheses sn-rediv0d.a ⊢ φ → A ∈ ℝ
sn-rediv0d.z ⊢ φ → A ≠ 0
Assertion sn-redividd ⊢ φ → A / ℝ A = 1

Proof

Step Hyp Ref Expression
1 sn-rediv0d.a ⊢ φ → A ∈ ℝ
2 sn-rediv0d.z ⊢ φ → A ≠ 0
3 eqidd ⊢ φ → A = A
4 1 1 2 rediveq1d ⊢ φ → A / ℝ A = 1 ↔ A = A
5 3 4 mpbird ⊢ φ → A / ℝ A = 1