Description: Two extension sequences have related endpoints iff they have the same base. (Contributed by Mario Carneiro, 1-Oct-2015)
Ref | Expression | ||
---|---|---|---|
Hypotheses | efgval.w | |
|
efgval.r | |
||
efgval2.m | |
||
efgval2.t | |
||
efgred.d | |
||
efgred.s | |
||
Assertion | efgcpbl2 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | efgval.w | |
|
2 | efgval.r | |
|
3 | efgval2.m | |
|
4 | efgval2.t | |
|
5 | efgred.d | |
|
6 | efgred.s | |
|
7 | 1 2 | efger | |
8 | 7 | a1i | |
9 | simpl | |
|
10 | 8 9 | ercl | |
11 | wrd0 | |
|
12 | 1 | efgrcl | |
13 | 10 12 | syl | |
14 | 13 | simprd | |
15 | 11 14 | eleqtrrid | |
16 | simpr | |
|
17 | 1 2 3 4 5 6 | efgcpbl | |
18 | 10 15 16 17 | syl3anc | |
19 | 10 14 | eleqtrd | |
20 | 8 16 | ercl | |
21 | 20 14 | eleqtrd | |
22 | ccatcl | |
|
23 | 19 21 22 | syl2anc | |
24 | ccatrid | |
|
25 | 23 24 | syl | |
26 | 8 16 | ercl2 | |
27 | 26 14 | eleqtrd | |
28 | ccatcl | |
|
29 | 19 27 28 | syl2anc | |
30 | ccatrid | |
|
31 | 29 30 | syl | |
32 | 18 25 31 | 3brtr3d | |
33 | 1 2 3 4 5 6 | efgcpbl | |
34 | 15 26 9 33 | syl3anc | |
35 | ccatlid | |
|
36 | 19 35 | syl | |
37 | 36 | oveq1d | |
38 | 8 9 | ercl2 | |
39 | 38 14 | eleqtrd | |
40 | ccatlid | |
|
41 | 39 40 | syl | |
42 | 41 | oveq1d | |
43 | 34 37 42 | 3brtr3d | |
44 | 8 32 43 | ertrd | |