This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: A weak universe is closed under partial mappings. (Contributed by Mario Carneiro, 2-Jan-2017)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | wun0.1 | ||
| wunop.2 | |||
| wunop.3 | |||
| Assertion | wunpm |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | wun0.1 | ||
| 2 | wunop.2 | ||
| 3 | wunop.3 | ||
| 4 | 1 3 2 | wunxp | |
| 5 | 1 4 | wunpw | |
| 6 | pmsspw | ||
| 7 | 6 | a1i | |
| 8 | 1 5 7 | wunss |