> {-# OPTIONS_HADDOCK show-extensions #-}
>
> module LTK.Decide.CB (isCB, isCBM) where
> import qualified Data.Set as Set
> import LTK.FSA
> import LTK.Algebra
>
> isCB :: (Ord n, Ord e) => FSA n e -> Bool
> isCB :: forall n e. (Ord n, Ord e) => FSA n e -> Bool
isCB = forall n e. (Ord n, Ord e) => SynMon n e -> Bool
isCBM forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall e n.
(Ord e, Ord n) =>
FSA n e -> FSA ([Maybe n], [Symbol e]) e
syntacticMonoid
>
> isCBM :: (Ord n, Ord e) => SynMon n e -> Bool
> isCBM :: forall n e. (Ord n, Ord e) => SynMon n e -> Bool
isCBM SynMon n e
m = forall n e. (FSA n e -> Set (Set (State n))) -> FSA n e -> Bool
trivialUnder forall e n.
(Ord e, Ord n) =>
FSA ([Maybe n], [Symbol e]) e
-> Set (Set (State ([Maybe n], [Symbol e])))
jEquivalence SynMon n e
m Bool -> Bool -> Bool
&& (Set (State ([Maybe n], [Symbol e]))
i forall a. Eq a => a -> a -> Bool
== forall e n. (Ord e, Ord n) => FSA n e -> Set (State n)
states SynMon n e
m)
> where i :: Set (State ([Maybe n], [Symbol e]))
i = forall a. Ord a => Set a -> Set a -> Set a
Set.union (forall n e. FSA n e -> Set (State n)
initials SynMon n e
m) (forall n e. (Ord n, Ord e) => FSA (n, [Symbol e]) e -> Set (T n e)
idempotents SynMon n e
m)