An operation is Semiombinable if you can combine two values using it, but there is no clearly defined neutral thing which you can combine with an element to obtain itself.

if there is a clearly definable neutral element, use FunLand.Combinable instead.

Fruit Salad Example

If you have one bowl with apples, and a second bowl with oranges, one can combine these, by putting the apples and the oranges in the same bowl.

This follows the Semicombinable law:

• associativity: combine(combine(bowl_with_apples, bowl_with_oranges), bowl_with_bananas) results in the same bowl as combine(bowl_with_apples, combine(bowl_with_oranges, bowl_with_bananas)) ## Some Common Semigroups - Strings (binaries) - List Concatenation - Algebraic Addition - Algebraic Multiplication Many semicombinables are not only 'semi', but fully Combinable. (See theCombinable` module) ## In Other Environments - In Category Theory, something that is Semicombinable is called a Semigroup.