theorem ltpr1tr (a b c: nat): $ a < b $ > $ a < b, c $;
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ltletr | a < b -> b <= b, c -> a < b, c | |
| 2 | hyp h | a < b | |
| 3 | 1, 2 | ax_mp | b <= b, c -> a < b, c | 
| 4 | leprid1 | b <= b, c | |
| 5 | 3, 4 | ax_mp | a < b, c |