Article · Wikipedia archive · Last revised Jun 4, 2026

Quantaloid

In mathematics, a quantaloid is a category enriched over the category Sup of complete lattices with supremum-preserving maps. In other words, for any objects a and b the Hom object between them is not just a set but a complete lattice, in such a way that composition of morphisms preserves all joins:

Last revised
Jun 4, 2026
Read time
≈ 1 min
Length
142 w
Citations
1
Source

In mathematics, a quantaloid is a category enriched over the category Sup of complete lattices with supremum-preserving maps.1 In other words, for any objects a and b the Hom object between them is not just a set but a complete lattice, in such a way that composition of morphisms preserves all joins:

( i f i ) ( j g j ) = i , j ( f i g j ) {\displaystyle (\bigvee _{i}f_{i})\circ (\bigvee _{j}g_{j})=\bigvee _{i,j}(f_{i}\circ g_{j})}

The endomorphism lattice H o m ( X , X ) {\displaystyle \mathrm {Hom} (X,X)} of any object X {\displaystyle X} in a quantaloid is a quantale, whence the name.

References

References

  1. Rosenthal, Kimmo I. (1996), The theory of quantaloids, Pitman Research Notes in Mathematics Series, vol. 348, Longman, Harlow, ISBN 0-582-29440-1, MR 1427263. See in particular p. 15.