Description: A function on the elements of an internal direct product has pairwise commuting values. (Contributed by Mario Carneiro, 25-Apr-2016) (Revised by AV, 11-Jul-2019)
Ref | Expression | ||
---|---|---|---|
Hypotheses | dprdff.w | |
|
dprdff.1 | |
||
dprdff.2 | |
||
dprdff.3 | |
||
dprdfcntz.z | |
||
Assertion | dprdfcntz | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dprdff.w | |
|
2 | dprdff.1 | |
|
3 | dprdff.2 | |
|
4 | dprdff.3 | |
|
5 | dprdfcntz.z | |
|
6 | eqid | |
|
7 | 1 2 3 4 6 | dprdff | |
8 | 7 | ffnd | |
9 | 7 | ffvelcdmda | |
10 | simpr | |
|
11 | 10 | fveq2d | |
12 | 10 | equcomd | |
13 | 12 | fveq2d | |
14 | 11 13 | oveq12d | |
15 | 2 | ad3antrrr | |
16 | 3 | ad3antrrr | |
17 | simpllr | |
|
18 | simplr | |
|
19 | simpr | |
|
20 | 15 16 17 18 19 5 | dprdcntz | |
21 | 1 2 3 4 | dprdfcl | |
22 | 21 | ad2antrr | |
23 | 20 22 | sseldd | |
24 | 1 2 3 4 | dprdfcl | |
25 | 24 | ad4ant13 | |
26 | eqid | |
|
27 | 26 5 | cntzi | |
28 | 23 25 27 | syl2anc | |
29 | 14 28 | pm2.61dane | |
30 | 29 | ralrimiva | |
31 | 8 | adantr | |
32 | oveq2 | |
|
33 | oveq1 | |
|
34 | 32 33 | eqeq12d | |
35 | 34 | ralrn | |
36 | 31 35 | syl | |
37 | 30 36 | mpbird | |
38 | 7 | frnd | |
39 | 38 | adantr | |
40 | 6 26 5 | elcntz | |
41 | 39 40 | syl | |
42 | 9 37 41 | mpbir2and | |
43 | 42 | ralrimiva | |
44 | ffnfv | |
|
45 | 8 43 44 | sylanbrc | |
46 | 45 | frnd | |