Description: The binary relation of a satisfaction predicate as function over wff codes is an increasing chain (with respect to inclusion). (Contributed by AV, 15-Oct-2023)
Ref | Expression | ||
---|---|---|---|
Hypothesis | satfsschain.s | |
|
Assertion | satfsschain | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | satfsschain.s | |
|
2 | fveq2 | |
|
3 | 2 | sseq2d | |
4 | 3 | imbi2d | |
5 | fveq2 | |
|
6 | 5 | sseq2d | |
7 | 6 | imbi2d | |
8 | fveq2 | |
|
9 | 8 | sseq2d | |
10 | 9 | imbi2d | |
11 | fveq2 | |
|
12 | 11 | sseq2d | |
13 | 12 | imbi2d | |
14 | ssidd | |
|
15 | 14 | a1i | |
16 | pm2.27 | |
|
17 | 16 | adantl | |
18 | simpr | |
|
19 | ssun1 | |
|
20 | simpl | |
|
21 | simpr | |
|
22 | simplll | |
|
23 | 1 | satfvsuc | |
24 | 20 21 22 23 | syl2an23an | |
25 | 19 24 | sseqtrrid | |
26 | 25 | adantr | |
27 | 18 26 | sstrd | |
28 | 27 | ex | |
29 | 17 28 | syld | |
30 | 29 | ex | |
31 | 30 | com23 | |
32 | 4 7 10 13 15 31 | findsg | |
33 | 32 | ex | |
34 | 33 | com23 | |
35 | 34 | impcom | |