Description: The restriction of a Toset is a Toset. (Contributed by Thierry Arnoux, 20-Jan-2018)
Ref | Expression | ||
---|---|---|---|
Assertion | resstos | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | tospos | |
|
2 | resspos | |
|
3 | 1 2 | sylan | |
4 | eqid | |
|
5 | eqid | |
|
6 | 4 5 | ressbas | |
7 | inss2 | |
|
8 | 6 7 | eqsstrrdi | |
9 | 8 | adantl | |
10 | eqid | |
|
11 | 5 10 | istos | |
12 | 11 | simprbi | |
13 | 12 | adantr | |
14 | ssralv | |
|
15 | ssralv | |
|
16 | 15 | ralimdv | |
17 | 14 16 | syld | |
18 | 9 13 17 | sylc | |
19 | 4 10 | ressle | |
20 | 19 | breqd | |
21 | 19 | breqd | |
22 | 20 21 | orbi12d | |
23 | 22 | 2ralbidv | |
24 | 23 | adantl | |
25 | 18 24 | mpbid | |
26 | eqid | |
|
27 | eqid | |
|
28 | 26 27 | istos | |
29 | 3 25 28 | sylanbrc | |