Description: Commutative/associative law for commutative rings. (Contributed by Jeff Madsen, 19-Jun-2010)
Ref | Expression | ||
---|---|---|---|
Hypotheses | crngm.1 | |
|
crngm.2 | |
||
crngm.3 | |
||
Assertion | crngm4 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | crngm.1 | |
|
2 | crngm.2 | |
|
3 | crngm.3 | |
|
4 | df-3an | |
|
5 | 1 2 3 | crngm23 | |
6 | 4 5 | sylan2br | |
7 | 6 | adantrrr | |
8 | 7 | oveq1d | |
9 | crngorngo | |
|
10 | 1 2 3 | rngocl | |
11 | 10 | 3expb | |
12 | 11 | adantrr | |
13 | simprrl | |
|
14 | simprrr | |
|
15 | 12 13 14 | 3jca | |
16 | 1 2 3 | rngoass | |
17 | 15 16 | syldan | |
18 | 9 17 | sylan | |
19 | 1 2 3 | rngocl | |
20 | 19 | 3expb | |
21 | 20 | adantrlr | |
22 | 21 | adantrrr | |
23 | simprlr | |
|
24 | 22 23 14 | 3jca | |
25 | 1 2 3 | rngoass | |
26 | 24 25 | syldan | |
27 | 9 26 | sylan | |
28 | 8 18 27 | 3eqtr3d | |
29 | 28 | 3impb | |