Description: Value of the submatrix. (Contributed by Thierry Arnoux, 19-Aug-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | smatfval | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elex | |
|
2 | 1 | 3ad2ant3 | |
3 | coeq1 | |
|
4 | 3 | mpoeq3dv | |
5 | df-smat | |
|
6 | nnex | |
|
7 | 6 6 | mpoex | |
8 | 4 5 7 | fvmpt | |
9 | 2 8 | syl | |
10 | breq2 | |
|
11 | 10 | ifbid | |
12 | 11 | opeq1d | |
13 | 12 | mpoeq3dv | |
14 | breq2 | |
|
15 | 14 | ifbid | |
16 | 15 | opeq2d | |
17 | 16 | mpoeq3dv | |
18 | 13 17 | sylan9eq | |
19 | 18 | adantl | |
20 | 19 | coeq2d | |
21 | simp1 | |
|
22 | simp2 | |
|
23 | simp3 | |
|
24 | 6 6 | mpoex | |
25 | 24 | a1i | |
26 | coexg | |
|
27 | 23 25 26 | syl2anc | |
28 | 9 20 21 22 27 | ovmpod | |