bottom-up and top-down filtering do not need fix point iteration.

src/GF/Speech/CFGToFiniteState.hs

@@ -64,7 +64,7 @@ cfgToFA opts s = minimize $ compileAutomaton start $ makeSimpleRegular opts s
 makeSimpleRegular :: Options -> StateGrammar -> CFRules
 makeSimpleRegular opts s = makeRegular $ preprocess $ cfgToCFRules s
   where start = getStartCatCF opts s
-        preprocess = fix (topDownFilter start . bottomUpFilter)
+        preprocess = topDownFilter start . bottomUpFilter
                      . removeCycles
 
 

src/GF/Speech/SRG.hs

@@ -93,10 +93,10 @@ makeSimpleSRG opt s = makeSRG preprocess opt s
                              . mergeIdentical
                              . traceStats "After removeLeftRecursion"
                              . removeLeftRecursion origStart 
-                             . fix (traceStats "After topDownFilter" 
-                                    . topDownFilter origStart 
-                                    . traceStats "After bottomUpFilter" 
-                                    . bottomUpFilter)
+                             . traceStats "After topDownFilter" 
+                             . topDownFilter origStart
+                             . traceStats "After bottomUpFilter"
+                             . bottomUpFilter
                              . traceStats "After removeCycles"
                              . removeCycles 
                              . traceStats "Inital CFG"

src/GF/Speech/TransformCFG.hs

@@ -109,7 +109,6 @@ bottomUpFilter gr = fix grow Map.empty
         okSym g = symbol (`elem` allCats g) (const True)
 
 -- | Removes categories which are not reachable from the start category.
--- Only does one pass through the grammar.
 topDownFilter :: Cat_ -> CFRules -> CFRules
 topDownFilter start rules = filterCFRulesCats (isRelatedTo uses start) rules
   where