trichotomy

tri- +‎ -chotomy; formed analogously from dichotomy as if it were from di- + -chotomy.

• (UK) IPA^(key): /tɹaɪˈkɒt.ə.mi/
• (US) IPA^(key): /tɹaɪˈkɑt.ə.mi/
• Rhymes: -ɒtəmi

trichotomy (countable and uncountable, plural trichotomies)

1. Division or separation into three groups or pieces.
2. (algebra) the property of an order relation whereby, given an ordered pair of elements (of a given algebraic structure), exactly one of these is true: the first element is 'less than' the second one, the second is 'less than' the first, or the two elements are equal.
   • Aliprantis, Border (2006), Infinite Dimensional Analysis: A Hitchhiker's Guide (3rd ed.), p. 6

     [A linear order] obeys the following trichotomy law[.]

• dichotomy
• trichotomous