Description: Ring multiplication distributes over subtraction. (Contributed by Jeff Madsen, 19-Jun-2010)
Ref | Expression | ||
---|---|---|---|
Hypotheses | ringsubdi.1 | |
|
ringsubdi.2 | |
||
ringsubdi.3 | |
||
ringsubdi.4 | |
||
Assertion | rngosubdir | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ringsubdi.1 | |
|
2 | ringsubdi.2 | |
|
3 | ringsubdi.3 | |
|
4 | ringsubdi.4 | |
|
5 | eqid | |
|
6 | 1 3 5 4 | rngosub | |
7 | 6 | 3adant3r3 | |
8 | 7 | oveq1d | |
9 | 1 2 3 | rngocl | |
10 | 9 | 3adant3r2 | |
11 | 1 2 3 | rngocl | |
12 | 11 | 3adant3r1 | |
13 | 10 12 | jca | |
14 | 1 3 5 4 | rngosub | |
15 | 14 | 3expb | |
16 | 13 15 | syldan | |
17 | idd | |
|
18 | 1 3 5 | rngonegcl | |
19 | 18 | ex | |
20 | idd | |
|
21 | 17 19 20 | 3anim123d | |
22 | 21 | imp | |
23 | 1 2 3 | rngodir | |
24 | 22 23 | syldan | |
25 | 1 2 3 5 | rngoneglmul | |
26 | 25 | 3adant3r1 | |
27 | 26 | oveq2d | |
28 | 24 27 | eqtr4d | |
29 | 16 28 | eqtr4d | |
30 | 8 29 | eqtr4d | |