@@ -66,7 +66,7 @@ relationFalse = Relation A.emptyAttributes emptyTupleSet
6666
6767--if the relation contains one tuple, return it, otherwise Nothing
6868singletonTuple :: Relation -> Maybe RelationTuple
69−singletonTuple rel@(Relation _ tupleSet) = if cardinality rel == Countable 1 then
69+singletonTuple rel@(Relation _ tupleSet) = if cardinality rel == Finite 1 then
7070 Just $ head $ asList tupleSet
7171 else
7272 Nothing
@@ -113,7 +113,7 @@ degree :: Relation -> Int
113113degree = arity
114114
115115cardinality :: Relation -> RelationCardinality --we need to detect infinite tuple sets- perhaps with a flag
116−cardinality (Relation _ tupSet) = Countable (length (asList tupSet))
116+cardinality (Relation _ tupSet) = Finite (length (asList tupSet))
117117
118118--find tuples where the atoms in the relation which are NOT in the AttributeNameSet are equal
119119-- create a relation for each tuple where the attributes NOT in the AttributeNameSet are equal