Description: Transfer an associative law to the function operation. (Contributed by Mario Carneiro, 26-Jul-2014)
Ref | Expression | ||
---|---|---|---|
Hypotheses | caofref.1 | |
|
caofref.2 | |
||
caofcom.3 | |
||
caofass.4 | |
||
caofass.5 | |
||
Assertion | caofass | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | caofref.1 | |
|
2 | caofref.2 | |
|
3 | caofcom.3 | |
|
4 | caofass.4 | |
|
5 | caofass.5 | |
|
6 | 5 | ralrimivvva | |
7 | 6 | adantr | |
8 | 2 | ffvelcdmda | |
9 | 3 | ffvelcdmda | |
10 | 4 | ffvelcdmda | |
11 | oveq1 | |
|
12 | 11 | oveq1d | |
13 | oveq1 | |
|
14 | 12 13 | eqeq12d | |
15 | oveq2 | |
|
16 | 15 | oveq1d | |
17 | oveq1 | |
|
18 | 17 | oveq2d | |
19 | 16 18 | eqeq12d | |
20 | oveq2 | |
|
21 | oveq2 | |
|
22 | 21 | oveq2d | |
23 | 20 22 | eqeq12d | |
24 | 14 19 23 | rspc3v | |
25 | 8 9 10 24 | syl3anc | |
26 | 7 25 | mpd | |
27 | 26 | mpteq2dva | |
28 | ovexd | |
|
29 | 2 | feqmptd | |
30 | 3 | feqmptd | |
31 | 1 8 9 29 30 | offval2 | |
32 | 4 | feqmptd | |
33 | 1 28 10 31 32 | offval2 | |
34 | ovexd | |
|
35 | 1 9 10 30 32 | offval2 | |
36 | 1 8 34 29 35 | offval2 | |
37 | 27 33 36 | 3eqtr4d | |