Description: Isomorphism is symmetric. (Contributed by AV, 5-Apr-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | cicsym | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cicrcl | |
|
2 | ciclcl | |
|
3 | eqid | |
|
4 | eqid | |
|
5 | simpl | |
|
6 | simpr | |
|
7 | 6 | adantl | |
8 | simpl | |
|
9 | 8 | adantl | |
10 | 3 4 5 7 9 | cic | |
11 | eqid | |
|
12 | 4 11 5 7 9 3 | isoval | |
13 | 4 11 5 9 7 | invsym2 | |
14 | 13 | eqcomd | |
15 | 14 | dmeqd | |
16 | df-rn | |
|
17 | 15 16 | eqtr4di | |
18 | 12 17 | eqtrd | |
19 | 18 | eleq2d | |
20 | vex | |
|
21 | elrng | |
|
22 | 20 21 | mp1i | |
23 | 19 22 | bitrd | |
24 | df-br | |
|
25 | 24 | exbii | |
26 | vex | |
|
27 | 26 20 | opeldm | |
28 | 4 11 5 9 7 3 | isoval | |
29 | 28 | eqcomd | |
30 | 29 | eleq2d | |
31 | 5 | adantr | |
32 | 9 | adantr | |
33 | 7 | adantr | |
34 | simpr | |
|
35 | 3 4 31 32 33 34 | brcici | |
36 | 35 | ex | |
37 | 30 36 | sylbid | |
38 | 27 37 | syl5com | |
39 | 38 | exlimiv | |
40 | 39 | com12 | |
41 | 25 40 | biimtrid | |
42 | 23 41 | sylbid | |
43 | 42 | exlimdv | |
44 | 10 43 | sylbid | |
45 | 44 | impancom | |
46 | 1 2 45 | mp2and | |