Description: The base set of a monoid is not empty. Statement in Lang p. 3. (Contributed by AV, 29-Dec-2023)
Ref | Expression | ||
---|---|---|---|
Hypothesis | mndbn0.b | |
|
Assertion | mndbn0 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | mndbn0.b | |
|
2 | eqid | |
|
3 | 1 2 | mndidcl | |
4 | 3 | ne0d | |