3 ms·
Types are not features, they are constraints. "at least all the properties of A" means "all of the constraints of A and some more". Subtype of A is more narrow
by hbrn 4y ago
Types are not features, they are constraints.
"at least all the properties of A" means "all of the constraints of A and some more". Subtype of A is more narrow than A, even if it means that object of subtype A has to have more fields.