let R be finite RelStr ; :: thesis: stability# R <= card the carrier of R
consider C being finite StableSet of R such that
A1: card C = stability# R by DILWORTH:def 6;
Segm (card C) c= Segm (card the carrier of R) by CARD_1:11;
hence stability# R <= card the carrier of R by A1, NAT_1:39; :: thesis: verum