diff --git a/util/Grid.h b/util/Grid.h
index 29e9e20..80f5055 100644
--- a/util/Grid.h
+++ b/util/Grid.h
@@ -7,6 +7,7 @@
 
 #include "MinigridGrammar.h"
 #include "PrismModulesPrinter.h"
+#include "PrismFormulaPrinter.h"
 #include "ConfigYaml.h"
 
 struct GridOptions {
@@ -59,6 +60,7 @@ class Grid {
     cells lockedDoors;
     cells unlockedDoors;
     cells boxes;
+    cells balls;
     cells lava;
 
     cells goals;
diff --git a/util/PrismFormulaPrinter.h b/util/PrismFormulaPrinter.h
index ac14cb4..058849d 100644
--- a/util/PrismFormulaPrinter.h
+++ b/util/PrismFormulaPrinter.h
@@ -16,11 +16,12 @@ std::map<ViewDirection, coordinates> getSurroundingCells(const cell &c);
 namespace prism {
   class PrismFormulaPrinter {
     public:
-      PrismFormulaPrinter(std::ostream &os, const AgentName &agentName, const std::map<std::string, cells> &restrictions, const cells &boxes, const cells &balls, const cells &lockedDoors, const cells &unlockedDoors, const cells &keys);
+      PrismFormulaPrinter(std::ostream &os, const AgentName &agentName, const std::map<std::string, cells> &restrictions, const cells &boxes, const cells &balls, const cells &lockedDoors, const cells &unlockedDoors, const cells &keys, const std::map<std::string, cells> &slipperyTiles, const cells &lava);
 
       void printFormulas();
 
       void printRestrictionFormula(const std::string &direction, const cells &grid_cells);
+      void printIsOnFormula(const std::string &type, const cells &grid_cells, const std::string &direction = "");
       void printRestrictionFormulaWithCondition(const std::string &reason, const std::map<ViewDirection, coordinates> &coordinates, const std::string &condition);
     private:
       std::string buildFormula(const std::string &formulaName, const std::string &formula);
@@ -36,6 +37,9 @@ namespace prism {
       cells lockedDoors;
       cells unlockedDoors;
       cells keys;
+      std::map<std::string, cells> slipperyTiles;
+      cells lava;
 
+      std::vector<std::string> conditionalMovementRestrictions;
   };
 }