Consider the relation S defined on the set of courses C above where c1 S c2 if and only if

 def relation_R(c1,c2): if c1==c2: return true if c1[0] == c2[0]: if c[1] < c[2]: return true return false def relation_S(c1,c2): if c1 == c2: return True if c1[0] == c2[0]: if c1[1] < c2[2]: return true elif c1[0]==c2[0]: if c1[3][0]==c2[3][0]: return true return false