Article · Wikipedia archive · Last revised Jul 19, 2026

Polyad (mathematics)

In mathematics, polyad is a concept of category theory introduced by Jean Bénabou in generalising monads. A polyad in a bicategory D is a bicategory morphism Φ from a locally punctual bicategory C to D, Φ : C → D. (A bicategory C is called locally punctual if all hom-categories C(X,Y) consist of one object and one morphism only.) Monads are polyads Φ : C → D where C has only one object.

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In mathematics, polyad is a concept of category theory introduced by Jean Bénabou in generalising monads.1 A polyad in a bicategory D is a bicategory morphism Φ from a locally punctual bicategory C to D, Φ : CD. (A bicategory C is called locally punctual if all hom-categories C(X,Y) consist of one object and one morphism only.) Monads are polyads Φ : CD where C has only one object.

Notes

Notes

  1. Benabou, Jean (1967), "Introduction to Bicategories", Reports of the Midwest Category Seminar, Lecture Notes in Mathematics, vol. 47, pp. 1–77, doi:10.1007/BFb0074299, ISBN 978-3-540-03918-1
Bibliography

Bibliography