| Metamath Proof Explorer |
< Previous
Next >
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 2526 |
. . 3
| |
| 2 | 1open.1 |
. . 3
| |
| 3 | 1, 2 | syl6ssr 2108 |
. 2
|
| 4 | 3 | adantl 388 |
1
|
| Colors of variables: wff set class |
| Syntax hints: |
| This theorem is referenced by: opncld 7674 clsval2 7685 ntrval2 7686 ntrss3 7692 cmclsopn 7693 opnneissb 7728 opnssneib 7729 opnneiss 7732 islp2 7747 iscnp2 7761 idcn 7766 homcard 10539 |
| This theorem was proved from axioms: ax-1 4 ax-2 5 ax-3 6 ax-mp 7 ax-7 962 ax-gen 963 ax-8 964 ax-10 966 ax-12 968 ax-17 971 ax-4 973 ax-5o 975 ax-6o 978 ax-9o 1123 ax-10o 1140 ax-16 1210 ax-11o 1218 ax-ext 1459 |
| This theorem depends on definitions: df-bi 147 df-an 225 df-ex 981 df-sb 1172 df-clab 1464 df-cleq 1469 df-clel 1472 df-v 1812 df-in 2051 df-ss 2053 df-uni 2504 |