Description: A subring is a subset. (Contributed by Stefan O'Rear, 27-Nov-2014)
Ref | Expression | ||
---|---|---|---|
Hypothesis | subrgss.1 | |
|
Assertion | subrgss | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | subrgss.1 | |
|
2 | eqid | |
|
3 | 1 2 | issubrg | |
4 | 3 | simprbi | |
5 | 4 | simpld | |