# Formal Definition

A Formal Definition is a Concept Definition in the form of a Formal Specification.

**AKA:**Formal Concept Definition.**Context:**- It can be a Mathematical Definition.
- It can be an Intensional Definition or an Extensional Definition.
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**Example(s):**`(forall (f s1 s2) (if (function0 f s1 s2)(domain s1 f)))`

, a Formal Sentence from a Function Domain.- Let
*B1*, ...,*Bn*and [math]\displaystyle{ D }[/math] be sets that are not necessarily Distinct Sets. A function F()*is a mapping of each Element combination [math]\displaystyle{ B }[/math] to an element of*D*.*

**See:**Formal, Formal Sentence.