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Related theorems Unicode version |
| Description: A member of a topology is a subset of its underlying set. |
| Ref | Expression |
|---|---|
| 1open.1 |
|
| Ref | Expression |
|---|---|
| eltopss |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elssuni 2530 |
. . 3
| |
| 2 | 1open.1 |
. . 3
| |
| 3 | 1, 2 | syl6ssr 2111 |
. 2
|
| 4 | 3 | adantl 390 |
1
|
| Colors of variables: wff set class |
| Syntax hints: |
| This theorem is referenced by: opncld 7671 clsval2 7682 ntrval2 7683 ntrss3 7689 cmclsopn 7690 opnneissb 7725 opnssneib 7726 opnneiss 7729 islp2 7744 iscnp2 7758 idcn 7763 homcard 10525 |
| This theorem was proved from axioms: ax-1 4 ax-2 5 ax-3 6 ax-mp 7 ax-7 964 ax-gen 965 ax-8 966 ax-10 968 ax-12 970 ax-17 973 ax-4 975 ax-5o 977 ax-6o 980 ax-9o 1125 ax-10o 1142 ax-16 1212 ax-11o 1220 ax-ext 1462 |
| This theorem depends on definitions: df-bi 147 df-an 225 df-ex 983 df-sb 1174 df-clab 1467 df-cleq 1472 df-clel 1475 df-v 1815 df-in 2054 df-ss 2056 df-uni 2508 |