Some authors require that be non-empty.
If is a structure, then the cardinality (or power) of , , is the cardinality of its .
Examples of structures abound in mathematics. Here are some of them:
If contains only relation symbols, then a -structure is called a relational structure. If contains only function symbols, then a -structure is called an algebraic structure. In the examples above, is a relation structure, while are algebraic structures.
|Date of creation||2013-05-20 18:26:21|
|Last modified on||2013-05-20 18:26:21|
|Last modified by||unlord (1)|