How is it called a Rel-morphism $(f;A;B)$ such that: a. $f=\varnothing$; b. $f\ne\varnothing$?
Is there any special term for this?
How is it called a Rel-morphism $(f;A;B)$ such that: a. $f=\varnothing$; b. $f\ne\varnothing$?
Is there any special term for this?