Description: Lemma for gchac (obsolete, used in Sierpiński's proof). (Contributed by Mario Carneiro, 15-May-2015)
Ref | Expression | ||
---|---|---|---|
Hypotheses | gchaclem.1 | |
|
gchaclem.3 | |
||
gchaclem.4 | |
||
Assertion | gchaclem | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | gchaclem.1 | |
|
2 | gchaclem.3 | |
|
3 | gchaclem.4 | |
|
4 | 3 | simpld | |
5 | reldom | |
|
6 | 5 | brrelex2i | |
7 | 4 6 | syl | |
8 | canth2g | |
|
9 | sdomdom | |
|
10 | 7 8 9 | 3syl | |
11 | domtr | |
|
12 | 4 10 11 | syl2anc | |
13 | 2 | adantr | |
14 | domtr | |
|
15 | 1 4 14 | syl2anc | |
16 | 15 | adantr | |
17 | pwdjuidm | |
|
18 | 16 17 | syl | |
19 | simpr | |
|
20 | gchdomtri | |
|
21 | 13 18 19 20 | syl3anc | |
22 | 21 | ex | |
23 | pwdom | |
|
24 | domtr | |
|
25 | 24 | ex | |
26 | 4 23 25 | 3syl | |
27 | 3 | simprd | |
28 | 26 27 | jaod | |
29 | 22 28 | syld | |
30 | 12 29 | jca | |