# Maths - Terminology

• extensionality, or extensional equality, refers to principles that judge objects to be equal if they have the same external properties.
• extension
• equaliser (category)
• fixpoint
• order complete -
• complete (category) (Negation Complete) (directed complete partial orders dcpo) - A category is complete if every diagram in C has a limit in C. In order theory completeness properties assert the existence of certain infima or suprema of a given partially ordered set (poset).
• canonicity - A type theory has canonicity if every term computes to a canonical form.
• preorder (set) (category) - A set with a binary relation which is reflexive and transitive.
• partial order
• poset
• axiom of choice
• classifier
• closure
• continuous
• exact functor
• generators
• Godels competeness theorem
• hom-set (category)
• inhabited
• kan extension (category)
• Lindenbaum Algebra
• natural number object
• powerset
• presheaf
• represention
• restriction
• section
• sieve
• weakly
• well founded
• well pointed