diff --git a/cmd/stages.go b/cmd/stages.go
index 6cc4a8b..f5e4b72 100644
--- a/cmd/stages.go
+++ b/cmd/stages.go
@@ -2,9 +2,12 @@ package cmd
 
 import (
 	"fmt"
-	bule "github.com/vale1410/bule/grounder"
+	"log"
 	"os"
 	"strconv"
+	"time"
+
+	bule "github.com/vale1410/bule/grounder"
 )
 
 func stage0Prerequisites(p *bule.Program) {
@@ -67,9 +70,10 @@ func stage1GeneratorsAndFacts(p *bule.Program) {
 			runFixpoint(p.ExpandGroundRanges),
 			"ExpandGroundRanges",
 			"p[1..2]. and also X==1..2, but not Y==A..B.")
+
 		stage(p, &changed,
 			p.ConstraintSimplification,
-			"Do Fixpoint of TransformConstraintsToInstantiation.",
+			"ConstraintSimplification.",
 			"For each constraint (X==v) rewrite clause with (X<-v) and remove constraint.")
 
 		stage(p, &changed,
@@ -89,7 +93,7 @@ func stage1GeneratorsAndFacts(p *bule.Program) {
 
 		stage(p, &changed,
 			p.ConstraintSimplification,
-			"Do Fixpoint of TransformConstraintsToInstantiation.",
+			"ConstraintSimplification.",
 			"For each constraint (X==v) rewrite clause with (X<-v) and remove constraint.")
 
 		stage(p, &changed,
@@ -111,7 +115,7 @@ func stage1GeneratorsAndFacts(p *bule.Program) {
 	stage(p, &changed,
 		p.RemoveRulesWithGenerators,
 		"RemoveRulesWithGeneratorsBecauseTheyHaveEmptyDomains",
-		"Because they have empty domains, e.g. \n edge[_,_,V] => vertex[V]. %% there are no edges!")
+		"Because they have empty domains, e.g. \n edge[_,_,V] :: vertex[V]. %% there are no edges!")
 }
 
 // Unroll all iterators.
@@ -240,6 +244,7 @@ func stage4Printing(p *bule.Program, args []string) {
 }
 
 func stage(p *bule.Program, change *bool, f func() (bool, error), stage string, info string) {
+	start := time.Now()
 	stageInfo(p, stage, info)
 	tmp, err := f()
 	if err != nil {
@@ -251,6 +256,9 @@ func stage(p *bule.Program, change *bool, f func() (bool, error), stage string,
 		debug(2, "Stage changed Program!")
 	}
 	*change = *change || tmp
+
+	elapsed := time.Since(start)
+	log.Printf("DEBUGTIME %6.2f %v %v", elapsed.Seconds(), stage, len(p.Rules))
 }
 
 func runFixpoint(f func() (bool, error)) func() (bool, error) {
diff --git a/grounder/ground.go b/grounder/ground.go
index 1ea0f78..2218ba3 100644
--- a/grounder/ground.go
+++ b/grounder/ground.go
@@ -14,6 +14,7 @@ import (
 func (p *Program) ConstraintSimplification() (bool, error) {
 
 	finalChanged := true
+	//start := time.Now()
 
 	i := 0
 	for {
@@ -22,6 +23,9 @@ func (p *Program) ConstraintSimplification() (bool, error) {
 		if err != nil {
 			return true, fmt.Errorf("Constraint simplification, iteration %v. \n %w", i, err)
 		}
+		//elapsed := time.Since(start)
+		//start = time.Now()
+		//log.Printf("X-DEBUGTIME %6.2f %v %v Constraints->Instantiation", elapsed.Seconds(), i, len(p.Rules))
 		if !changed {
 			//Debug(2, "Remove clauses with contradictions, e.g.  (1==2) or (1!=1),  and remove true constraints, e.g.  (1>2, 1==1).")
 			finalChanged, err = p.CleanRulesFromGroundBoolExpression()
@@ -30,6 +34,9 @@ func (p *Program) ConstraintSimplification() (bool, error) {
 			}
 			break
 		}
+		//elapsed = time.Since(start)
+		//start = time.Now()
+		//log.Printf("X-DEBUGTIME %6.2f %v %v CleanRules", elapsed.Seconds(), i, len(p.Rules))
 	}
 	return finalChanged || i > 1, nil
 }
@@ -153,6 +160,7 @@ func (p *Program) findFilteredTuples(literal Literal) [][]string {
 			filteredTuples = append(filteredTuples, tuple)
 		}
 	}
+	//	fmt.Println("DEBUG", literal, filteredTuples)
 	return filteredTuples
 }
 
@@ -421,6 +429,11 @@ func (p *Program) CleanRulesFromGroundBoolExpression() (bool, error) {
 				return true
 			}
 		}
+		for _, lit := range r.Generators {
+			if p.FinishCollectingFacts[lit.Name] && lit.IsGround() {
+				return true
+			}
+		}
 		return false
 	}
 
@@ -437,6 +450,22 @@ func (p *Program) CleanRulesFromGroundBoolExpression() (bool, error) {
 				newRule.Constraints = append(newRule.Constraints, cons)
 			}
 		}
+		newRule.Generators = []Literal{}
+		for _, lit := range rule.Generators {
+			if p.FinishCollectingFacts[lit.Name] && lit.IsGround() {
+				//				fmt.Println("DEBUG", lit.IdString(), "\n", p.FinishCollectingFacts, "\n", p.PredicateTupleMap)
+				if lit.Neg && p.PredicateTupleMap[lit.createNegatedLiteral().IdString()] {
+					//					fmt.Println("DEBUG REMOVE", rule.String())
+					return []Rule{}, nil
+				} else if !lit.Neg && p.PredicateTupleMap[lit.IdString()] {
+					//					fmt.Println("DEBUG DO NOT REMOVE", rule.String())
+				} else {
+					newRule.Generators = append(newRule.Generators, lit)
+				}
+			} else {
+				newRule.Generators = append(newRule.Generators, lit)
+			}
+		}
 		return []Rule{newRule}, nil
 	}
 	return p.RuleExpansion(check, transform)
diff --git a/grounder/transformation.go b/grounder/transformation.go
index ef25fc2..7dd05da 100644
--- a/grounder/transformation.go
+++ b/grounder/transformation.go
@@ -2,6 +2,7 @@ package grounder
 
 import (
 	"fmt"
+
 	"github.com/scylladb/go-set/strset"
 )
 
@@ -143,30 +144,6 @@ func TermTranslation(termIterator TermIterator, transform func(Term) (Term, bool
 	return
 }
 
-//func (iterator *Iterator) TermTranslation(transform func(Term) (Term, bool, error)) (changed bool, err error) {
-//	var ok bool
-//	for _, term := range iterator.AllTerms() {
-//		*term, ok, err = transform(*term)
-//		changed = ok || changed
-//		if err != nil {
-//			return changed, err
-//		}
-//	}
-//	return
-//}
-//
-//func (rule *Rule) TermTranslation(transform func(Term) (Term, bool, error)) (changed bool, err error) {
-//	var ok bool
-//	for _, term := range rule.AllTerms() {
-//		*term, ok, err = transform(*term)
-//		changed = ok || changed
-//		if err != nil {
-//			return changed, err
-//		}
-//	}
-//	return
-//}
-
 func (iterator Iterator) AllTerms() (terms []*Term) {
 
 	for i := range iterator.Head.Terms {