Week 4: Ex 7

[BertLisser]

qcTestContainsRelTc = verboseCheck (\c -> containsRel c (trClos c))

and

cTestIsTransitive = verboseCheck (\c -> isTransitive (trClos c))

must become

verboseCheck (\x->  containsRel x (trClos x) && isTransitive (trClos x))

Both properties must be simultaneously valid.

Good (=8)

[ikmarlin]

Hi Bert,

qcTestContainsRelTc checks that the original relation is part of the closure

qcTestIsTransitive checks that the relation is transitive

qcTestIsTrClos however, checks for the 3 properties (contains original relation, is transitive and is minimal). I'm not sure if it's correct according to your suggestion, but the 2 checks you're referring to are indeed not the test to check if the relation is a transitive closure.

qcTestIsTrClos :: IO ()
qcTestIsTrClos = verboseCheck (\c -> let cl = trClos c in isTransitive cl ==> containsRel c cl ==> isMinimumTC cl c)