Description: Part of proof of Lemma G of Crawley p. 116, ninth line of third paragraph on p. 117: "we conclude that gf = fg." (Contributed by NM, 5-Jun-2013)
Ref | Expression | ||
---|---|---|---|
Hypotheses | cdlemg46.b | |
|
cdlemg46.h | |
||
cdlemg46.t | |
||
cdlemg46.r | |
||
Assertion | cdlemg47 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cdlemg46.b | |
|
2 | cdlemg46.h | |
|
3 | cdlemg46.t | |
|
4 | cdlemg46.r | |
|
5 | simp11 | |
|
6 | simp2l | |
|
7 | simp12 | |
|
8 | 2 3 | ltrnco | |
9 | 5 6 7 8 | syl3anc | |
10 | simp13 | |
|
11 | simp3 | |
|
12 | 1 2 3 4 | cdlemg46 | |
13 | 5 7 6 11 12 | syl121anc | |
14 | simp2r | |
|
15 | 13 14 | neeqtrd | |
16 | 2 3 4 | cdlemg44 | |
17 | 5 9 10 15 16 | syl121anc | |
18 | coass | |
|
19 | 17 18 | eqtr4di | |
20 | simp33 | |
|
21 | 20 14 | neeqtrd | |
22 | 2 3 4 | cdlemg44 | |
23 | 5 6 10 21 22 | syl121anc | |
24 | 23 | coeq1d | |
25 | 19 24 | eqtr4d | |
26 | coass | |
|
27 | coass | |
|
28 | 25 26 27 | 3eqtr3g | |
29 | 28 | coeq2d | |
30 | coass | |
|
31 | 1 2 3 | ltrn1o | |
32 | 5 6 31 | syl2anc | |
33 | f1ococnv1 | |
|
34 | 32 33 | syl | |
35 | 34 | coeq1d | |
36 | 30 35 | eqtr3id | |
37 | 2 3 | ltrnco | |
38 | 5 7 10 37 | syl3anc | |
39 | 1 2 3 | ltrn1o | |
40 | 5 38 39 | syl2anc | |
41 | f1of | |
|
42 | fcoi2 | |
|
43 | 40 41 42 | 3syl | |
44 | 36 43 | eqtrd | |
45 | coass | |
|
46 | 34 | coeq1d | |
47 | 45 46 | eqtr3id | |
48 | 2 3 | ltrnco | |
49 | 5 10 7 48 | syl3anc | |
50 | 1 2 3 | ltrn1o | |
51 | 5 49 50 | syl2anc | |
52 | f1of | |
|
53 | fcoi2 | |
|
54 | 51 52 53 | 3syl | |
55 | 47 54 | eqtrd | |
56 | 29 44 55 | 3eqtr3d | |