Description: Substitution law for segment comparison under congruence. Biconditional version. (Contributed by Scott Fenton, 15-Oct-2013) (Revised by Mario Carneiro, 19-Apr-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | seglecgr12 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-3an | |
|
2 | seglecgr12im | |
|
3 | 1 2 | biimtrrid | |
4 | 3 | expd | |
5 | simp11 | |
|
6 | simp12 | |
|
7 | simp13 | |
|
8 | simp23 | |
|
9 | simp31 | |
|
10 | cgrcom | |
|
11 | 5 6 7 8 9 10 | syl122anc | |
12 | simp21 | |
|
13 | simp22 | |
|
14 | simp32 | |
|
15 | simp33 | |
|
16 | cgrcom | |
|
17 | 5 12 13 14 15 16 | syl122anc | |
18 | 11 17 | anbi12d | |
19 | df-3an | |
|
20 | seglecgr12im | |
|
21 | 5 8 9 14 15 6 7 12 13 20 | syl333anc | |
22 | 19 21 | biimtrrid | |
23 | 22 | expd | |
24 | 18 23 | sylbid | |
25 | 4 24 | impbidd | |