This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: If an atom is not less than or equal to the join of two others, it is not equal to either. (This also holds for non-atoms, but in this form it is convenient.) (Contributed by NM, 8-Jan-2012)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | atnlej.l | ||
| atnlej.j | |||
| atnlej.a | |||
| Assertion | atnlej2 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | atnlej.l | ||
| 2 | atnlej.j | ||
| 3 | atnlej.a | ||
| 4 | hllat | ||
| 5 | 4 | 3ad2ant1 | |
| 6 | simp21 | ||
| 7 | eqid | ||
| 8 | 7 3 | atbase | |
| 9 | 6 8 | syl | |
| 10 | simp22 | ||
| 11 | 7 3 | atbase | |
| 12 | 10 11 | syl | |
| 13 | simp23 | ||
| 14 | 7 3 | atbase | |
| 15 | 13 14 | syl | |
| 16 | simp3 | ||
| 17 | 7 1 2 | latnlej1r | |
| 18 | 5 9 12 15 16 17 | syl131anc |