This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: If A belongs to a part of C , then A belongs to C . (Contributed by FL, 3-Aug-2009)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | elelpwi |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elpwi | ||
| 2 | 1 | sseld | |
| 3 | 2 | impcom |