Description: A number minus 1 is less than or equal to itself. (Contributed by Mario Carneiro, 28-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | ltp1d.1 | |- ( ph -> A e. RR ) |
|
| Assertion | lem1d | |- ( ph -> ( A - 1 ) <_ A ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ltp1d.1 | |- ( ph -> A e. RR ) |
|
| 2 | lem1 | |- ( A e. RR -> ( A - 1 ) <_ A ) |
|
| 3 | 1 2 | syl | |- ( ph -> ( A - 1 ) <_ A ) |