theorem ltpr2tr (a b c: nat): $ a < c $ > $ a < b, c $;
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ltletr | a < c -> c <= b, c -> a < b, c |
|
| 2 | hyp h | a < c |
|
| 3 | 1, 2 | ax_mp | c <= b, c -> a < b, c |
| 4 | leprid2 | c <= b, c |
|
| 5 | 3, 4 | ax_mp | a < b, c |