:: deftheorem defines ex_sup_of YELLOW_0:def 7 :
for L being RelStr
for X being set holds
( ex_sup_of X,L iff ex a being Element of L st
( X is_<=_than a & ( for b being Element of L st X is_<=_than b holds
b >= a ) & ( for c being Element of L st X is_<=_than c & ( for b being Element of L st X is_<=_than b holds
b >= c ) holds
c = a ) ) );