Complement
Set
| context | $X,Y\in \mathfrak U$ |
| definiendum | $ x\in X \smallsetminus Y $ |
| postulate | $ x\in X $ |
| postulate | $ x\notin Y $ |
Discussion
Reference
Wikipedia: Complement
| context | $X,Y\in \mathfrak U$ |
| definiendum | $ x\in X \smallsetminus Y $ |
| postulate | $ x\in X $ |
| postulate | $ x\notin Y $ |
Wikipedia: Complement