Description: The adder sequence function is commutative. (Contributed by Mario Carneiro, 5-Sep-2016)
Ref | Expression | ||
---|---|---|---|
Assertion | sadcom | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | hadcoma | |
|
2 | 1 | a1i | |
3 | 2 | rabbidv | |
4 | simpl | |
|
5 | simpr | |
|
6 | eqid | |
|
7 | 4 5 6 | sadfval | |
8 | cadcoma | |
|
9 | 8 | a1i | |
10 | 9 | ifbid | |
11 | 10 | mpoeq3ia | |
12 | seqeq2 | |
|
13 | 11 12 | ax-mp | |
14 | 5 4 13 | sadfval | |
15 | 3 7 14 | 3eqtr4d | |