diff --git a/util/Grid.cpp b/util/Grid.cpp
index 2f294c4..2e44298 100644
--- a/util/Grid.cpp
+++ b/util/Grid.cpp
@@ -15,6 +15,10 @@ Grid::Grid(cells gridCells, cells background, const std::map<coordinates, float>
   std::copy_if(background.begin(), background.end(), std::back_inserter(slipperyEast),  [](cell c) { return c.type == Type::SlipperyEast; });
   std::copy_if(background.begin(), background.end(), std::back_inserter(slipperySouth), [](cell c) { return c.type == Type::SlipperySouth; });
   std::copy_if(background.begin(), background.end(), std::back_inserter(slipperyWest),  [](cell c) { return c.type == Type::SlipperyWest; });
+  std::copy_if(background.begin(), background.end(), std::back_inserter(slipperyNorthWest), [](cell c) { return c.type == Type::SlipperyNorthWest; });
+  std::copy_if(background.begin(), background.end(), std::back_inserter(slipperyNorthEast), [](cell c) { return c.type == Type::SlipperyNorthEast; });
+  std::copy_if(background.begin(), background.end(), std::back_inserter(slipperySouthWest), [](cell c) { return c.type == Type::SlipperySouthWest; });
+  std::copy_if(background.begin(), background.end(), std::back_inserter(slipperySouthEast), [](cell c) { return c.type == Type::SlipperySouthEast; });
   std::copy_if(gridCells.begin(),  gridCells.end(),  std::back_inserter(lockedDoors),   [](cell c) { return c.type == Type::LockedDoor; });
   std::copy_if(gridCells.begin(),  gridCells.end(),  std::back_inserter(unlockedDoors), [](cell c) { return c.type == Type::Door; });
   std::copy_if(gridCells.begin(),  gridCells.end(),  std::back_inserter(goals),         [](cell c) { return c.type == Type::Goal; });
@@ -157,7 +161,7 @@ void Grid::printToPrism(std::ostream& os, std::vector<Configuration>& configurat
 
 
   std::map<std::string, cells> wallRestrictions = {{"North", northRestriction}, {"East", eastRestriction}, {"South", southRestriction}, {"West", westRestriction}};
-  std::map<std::string, cells> slipperyTiles    = {{"North", slipperyNorth}, {"East", slipperyEast}, {"South", slipperySouth}, {"West", slipperyWest}};
+  std::map<std::string, cells> slipperyTiles    = {{"North", slipperyNorth}, {"East", slipperyEast}, {"South", slipperySouth}, {"West", slipperyWest}, {"NorthWest", slipperyNorthWest}, {"NorthEast", slipperyNorthEast},{"SouthWest", slipperySouthWest},{"SouthEast", slipperySouthEast}};
 
   std::vector<AgentName> agentNames;
   std::transform(agentNameAndPositionMap.begin(),
diff --git a/util/Grid.h b/util/Grid.h
index 3d7f23d..f741473 100644
--- a/util/Grid.h
+++ b/util/Grid.h
@@ -46,6 +46,10 @@ class Grid {
     cells slipperyEast;
     cells slipperySouth;
     cells slipperyWest;
+    cells slipperyNorthWest;
+    cells slipperyNorthEast;
+    cells slipperySouthWest;
+    cells slipperySouthEast;
     cells lockedDoors;
     cells unlockedDoors;
     cells boxes;
diff --git a/util/MinigridGrammar.h b/util/MinigridGrammar.h
index e2cfddc..ea6c1cf 100644
--- a/util/MinigridGrammar.h
+++ b/util/MinigridGrammar.h
@@ -66,6 +66,10 @@ template <typename It>
       ("e", Type::SlipperyEast)
       ("s", Type::SlipperySouth)
       ("w", Type::SlipperyWest)
+      ("a", Type::SlipperyNorthWest)
+      ("b", Type::SlipperyNorthEast)
+      ("c", Type::SlipperySouthWest)
+      ("d", Type::SlipperySouthEast)
       ("X", Type::Agent)
       ("Z", Type::Adversary);
     color_.add
@@ -74,8 +78,9 @@ template <typename It>
       ("B", Color::Blue)
       ("P", Color::Purple)
       ("Y", Color::Yellow)
+      ("W", Color::White)
       (" ", Color::None);
-  
+
     cell_ = type_ > color_;
 
     row_ = (cell_ % -qi::char_("\n"));
diff --git a/util/cell.h b/util/cell.h
index ca71559..5e69e3b 100644
--- a/util/cell.h
+++ b/util/cell.h
@@ -23,7 +23,11 @@ enum class Type : char {
   SlipperyNorth = 'n',
   SlipperySouth = 's',
   SlipperyEast  = 'e',
-  SlipperyWest  = 'w'
+  SlipperyWest  = 'w',
+  SlipperyNorthWest = 'a',
+  SlipperyNorthEast = 'b',
+  SlipperySouthWest = 'c',
+  SlipperySouthEast = 'd'
 };
 enum class Color : char {
   Red    = 'R',
@@ -31,6 +35,7 @@ enum class Color : char {
   Blue   = 'B',
   Purple = 'P',
   Yellow = 'Y',
+  White  = 'W',
   //Grey   = 'G',
   None   = ' '
 };