Description: A number divided by 1 is itself. (Contributed by SN, 2-Apr-2026)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | sn-rediv1d.a | |- ( ph -> A e. RR ) |
|
| Assertion | sn-rediv1d | |- ( ph -> ( A /R 1 ) = A ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sn-rediv1d.a | |- ( ph -> A e. RR ) |
|
| 2 | remullid | |- ( A e. RR -> ( 1 x. A ) = A ) |
|
| 3 | 1 2 | syl | |- ( ph -> ( 1 x. A ) = A ) |
| 4 | 1red | |- ( ph -> 1 e. RR ) |
|
| 5 | ax-1ne0 | |- 1 =/= 0 |
|
| 6 | 5 | a1i | |- ( ph -> 1 =/= 0 ) |
| 7 | 1 1 4 6 | redivmuld | |- ( ph -> ( ( A /R 1 ) = A <-> ( 1 x. A ) = A ) ) |
| 8 | 3 7 | mpbird | |- ( ph -> ( A /R 1 ) = A ) |