Description: Permutation law for three-place congruence. (Contributed by Scott Fenton, 5-Oct-2013)
Ref | Expression | ||
---|---|---|---|
Assertion | cgr3permute1 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | id | |
|
2 | 3simpc | |
|
3 | 3simpc | |
|
4 | cgrcomlr | |
|
5 | 1 2 3 4 | syl3an | |
6 | 5 | 3anbi3d | |
7 | 3ancoma | |
|
8 | 6 7 | bitrdi | |
9 | brcgr3 | |
|
10 | biid | |
|
11 | 3ancomb | |
|
12 | 3ancomb | |
|
13 | brcgr3 | |
|
14 | 10 11 12 13 | syl3anb | |
15 | 8 9 14 | 3bitr4d | |