In logic and mathematics, relation construction and relational constructibility have to do with the ways that one relation is determined by an indexed family or a sequence of other relations, called the relation dataset. The relation in the focus of consideration is called the faciendum. The relation dataset typically consists of a specified relation over sets of relations, called the constructor, the factor, or the method of construction, plus a specified set of other relations, called the faciens, the ingredients, or the makings.
Relation composition and relation reduction are special cases of relation constructions.