Description: If two pairs of numbers are componentwise congruent, so are their sums. (Contributed by Stefan O'Rear, 1-Oct-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | congadd | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpl1 | |
|
2 | zsubcl | |
|
3 | 2 | 3adant1 | |
4 | 3 | adantr | |
5 | zsubcl | |
|
6 | 5 | adantl | |
7 | dvds2add | |
|
8 | 1 4 6 7 | syl3anc | |
9 | 8 | 3impia | |
10 | simpl2 | |
|
11 | 10 | zcnd | |
12 | zcn | |
|
13 | 12 | ad2antrl | |
14 | simpl3 | |
|
15 | 14 | zcnd | |
16 | zcn | |
|
17 | 16 | ad2antll | |
18 | 11 13 15 17 | addsub4d | |
19 | 18 | 3adant3 | |
20 | 9 19 | breqtrrd | |