Description: The group addition operation is a function. (Contributed by Mario Carneiro, 14-Aug-2015)
Ref | Expression | ||
---|---|---|---|
Hypotheses | grpplusf.1 | |
|
grpplusf.2 | |
||
Assertion | grpplusf | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | grpplusf.1 | |
|
2 | grpplusf.2 | |
|
3 | grpmnd | |
|
4 | 1 2 | mndplusf | |
5 | 3 4 | syl | |