英和和英

名詞

nonreflexivity (uncountable)

1. (logic, mathematics) The property of a binary relation that is not reflexive; that is, there exists at least one x such that not Rxx.
   • 2001, Patrick Blackburn, Maarten de Rijke, Yde Venema, Modal Logic, Cambridge University Press, page 97:

     A relation is nonreflexive if it is not reflexive, i.e., if there is a point that is not R-related to itself.

使用する際の注意点

Nonreflexivity is not to be confused with irreflexivity. A relation is irreflexive if for all x, not Rxx. A relation is nonreflexive if there exists at least one x such that not Rxx, but may still have some x for which Rxx holds. e.g. The relation "likes" on a set of people is typically nonreflexive: a person may like themselves (Rxx) or not, but the relation is not reflexive because not everyone likes themselves.

反意語

• reflexivity

等位語

• irreflexivity