Better simplification of prism commands.

src/storm/storage/prism/Command.cpp

@@ -85,9 +85,10 @@ namespace storm {
             std::vector<Update> newUpdates;
             newUpdates.reserve(this->getNumberOfUpdates());
             for (auto const& update : this->getUpdates()) {
-                newUpdates.emplace_back(update.removeIdentityAssignments());
+                newUpdates.emplace_back(update.simplify());
             }
-            return copyWithNewUpdates(std::move(newUpdates));
+            auto simpleGuard = guardExpression.simplify().reduceNesting();
+            return Command(this->globalIndex, this->markovian, this->getActionIndex(), this->getActionName(), simpleGuard, newUpdates, this->getFilename(), this->getLineNumber());
         }
         
         Command Command::copyWithNewUpdates(std::vector<Update> && newUpdates) const {

src/storm/storage/prism/Update.cpp

@@ -87,6 +87,18 @@ namespace storm {
             return Update(this->globalIndex, this->likelihoodExpression, newAssignments, getFilename(), getLineNumber());
         }
         
+        Update Update::simplify() const {
+            std::vector<Assignment> newAssignments;
+            newAssignments.reserve(getNumberOfAssignments());
+            for (auto const& ass : this->assignments) {
+                Assignment newAssignment(ass.getVariable(), ass.getExpression().simplify().reduceNesting(), ass.getFilename(), ass.getLineNumber());
+                if (!newAssignment.isIdentity()) {
+                    newAssignments.push_back(std::move(newAssignment));
+                }
+            }
+            return Update(this->globalIndex, this->likelihoodExpression.simplify().reduceNesting(), newAssignments, getFilename(), getLineNumber());
+        }
+        
         std::ostream& operator<<(std::ostream& stream, Update const& update) {
             stream << update.getLikelihoodExpression() << " : ";
             if (update.getAssignments().empty()) {

src/storm/storage/prism/Update.h

@@ -93,6 +93,11 @@ namespace storm {
              */
             Update removeIdentityAssignments() const;
             
+            /*!
+             * Simplifies the update in various ways (also removes identity assignments)
+             */
+            Update simplify() const;
+            
             friend std::ostream& operator<<(std::ostream& stream, Update const& assignment);
             
         private: