Talk:Correlation inequalities

Order ideals or down-sets

The introductory paragraph reads let $A$and $B$ be order ideals or down-sets in $(S,{\subset})$. However, the discussion at Ideal and Filter suggests that it is usual to impose the extra condition that an ideal contain the supremum of any two elements, which is not, I think, required here. Richard Pinch (talk) 22:54, 2 May 2020 (CEST)