:: deftheorem defines os-compatible OSALG_4:def 1 :
for R being non empty Poset
for A, B being ManySortedSet of the carrier of R
for IT being ManySortedRelation of A,B holds
( IT is os-compatible iff for s1, s2 being Element of R st s1 <= s2 holds
for x, y being set st x in A . s1 & y in B . s1 holds
( [x,y] in IT . s1 iff [x,y] in IT . s2 ) );