A groupoid is a structure A = (A,·) where · is any binary operation on A.
Let A and B be groupoids. A morphism from A to B is a function h : A→B that is a homomorphism: h(x·y) = h(x)·h(y).
|Congruence extension property||no|
|Definable principal congruences||no|
|Equationally definable principal congruences||no|
|Strong amalgamation property||yes|
|Epimorphisms are surjective||yes|