Metamath Proof Explorer


Theorem sn-rediv1d

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

Ref Expression
Hypothesis sn-rediv1d.a φ A
Assertion sn-rediv1d φ A / 1 = A

Proof

Step Hyp Ref Expression
1 sn-rediv1d.a φ A
2 remullid A 1 A = A
3 1 2 syl φ 1 A = A
4 1red φ 1
5 ax-1ne0 1 0
6 5 a1i φ 1 0
7 1 1 4 6 redivmuld φ A / 1 = A 1 A = A
8 3 7 mpbird φ A / 1 = A