diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/Renderers.java b/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/Renderers.java
index 826f4b94502..a21b96a2f10 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/Renderers.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/Renderers.java
@@ -40,8 +40,11 @@ import org.jetbrains.jet.renderer.Renderer;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Set;
 
 import static org.jetbrains.jet.lang.diagnostics.rendering.TabledDescriptorRenderer.*;
+import static org.jetbrains.jet.lang.resolve.calls.inference.TypeBounds.BoundKind.LOWER_BOUND;
+import static org.jetbrains.jet.lang.resolve.calls.inference.TypeBounds.BoundKind.UPPER_BOUND;
 
 public class Renderers {
     public static final Renderer<Object> TO_STRING = new Renderer<Object>() {
@@ -342,6 +345,45 @@ public class Renderers {
         }
     };
 
+    public static final Renderer<ConstraintSystem> RENDER_CONSTRAINT_SYSTEM = new Renderer<ConstraintSystem>() {
+        @NotNull
+        @Override
+        public String render(@NotNull ConstraintSystem constraintSystem) {
+            Set<TypeParameterDescriptor> typeVariables = constraintSystem.getTypeVariables();
+            Set<TypeBounds> typeBounds = Sets.newLinkedHashSet();
+            for (TypeParameterDescriptor variable : typeVariables) {
+                typeBounds.add(constraintSystem.getTypeBounds(variable));
+            }
+            Function<TypeBounds, String> renderTypeBounds = rendererToFunction(RENDER_TYPE_BOUNDS);
+            return "type parameter bounds: \n" + StringUtil.join(typeBounds, renderTypeBounds, ";\n") + "\n" +
+                   "status:\n" + ConstraintsUtil.getDebugMessageForStatus(constraintSystem.getStatus());
+        }
+    };
+
+    public static final Renderer<TypeBounds> RENDER_TYPE_BOUNDS = new Renderer<TypeBounds>() {
+        @NotNull
+        @Override
+        public String render(@NotNull TypeBounds typeBounds) {
+            Function<TypeBoundsImpl.Bound, String> renderBound = new Function<TypeBoundsImpl.Bound, String>() {
+                @Override
+                public String fun(TypeBoundsImpl.Bound bound) {
+                    String arrow = bound.kind == LOWER_BOUND ? "<: " : bound.kind == UPPER_BOUND ? ">: " : "=  ";
+                    return arrow + bound.type + '(' + bound.position + ')';
+                }
+            };
+            return typeBounds.getTypeVariable().getName() + " " + StringUtil.join(typeBounds.getBounds(), renderBound, ", ");
+        }
+    };
+
+    @NotNull
+    public static <T> Function<T, String> rendererToFunction(final @NotNull Renderer<T> renderer) {
+        return new Function<T, String>() {
+            @Override
+            public String fun(T t) {
+                return renderer.render(t);
+            }
+        };
+    }
 
     private Renderers() {
     }
diff --git a/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystemImpl.java b/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystemImpl.java
index 6e71662f2bf..109a51ab5a0 100644
--- a/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystemImpl.java
+++ b/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystemImpl.java
@@ -40,8 +40,8 @@ import java.util.Set;
 
 import static org.jetbrains.jet.lang.resolve.calls.inference.ConstraintSystemImpl.ConstraintKind.EQUAL;
 import static org.jetbrains.jet.lang.resolve.calls.inference.ConstraintSystemImpl.ConstraintKind.SUB_TYPE;
-import static org.jetbrains.jet.lang.resolve.calls.inference.TypeBoundsImpl.BoundKind.*;
-import static org.jetbrains.jet.lang.resolve.calls.inference.TypeBoundsImpl.Bound;
+import static org.jetbrains.jet.lang.resolve.calls.inference.TypeBounds.BoundKind.*;
+import static org.jetbrains.jet.lang.resolve.calls.inference.TypeBounds.Bound;
 import static org.jetbrains.jet.lang.types.TypeUtils.CANT_INFER_TYPE_PARAMETER;
 import static org.jetbrains.jet.lang.types.TypeUtils.DONT_CARE;
 
diff --git a/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/TypeBounds.java b/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/TypeBounds.java
index c43d3eae8b3..e9b67f24a87 100644
--- a/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/TypeBounds.java
+++ b/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/TypeBounds.java
@@ -18,16 +18,22 @@ package org.jetbrains.jet.lang.resolve.calls.inference;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor;
 import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lang.types.Variance;
 
 import java.util.Collection;
-import java.util.Set;
 
 public interface TypeBounds {
     @NotNull
     Variance getVarianceOfPosition();
 
+    @NotNull
+    TypeParameterDescriptor getTypeVariable();
+
+    @NotNull
+    Collection<Bound> getBounds();
+
     boolean isEmpty();
 
     @Nullable
@@ -35,4 +41,20 @@ public interface TypeBounds {
 
     @NotNull
     Collection<JetType> getValues();
+
+    enum BoundKind {
+        LOWER_BOUND, UPPER_BOUND, EXACT_BOUND
+    }
+
+    class Bound {
+        public final JetType type;
+        public final BoundKind kind;
+        public final ConstraintPosition position;
+
+        public Bound(@NotNull JetType type, @NotNull BoundKind kind, @NotNull ConstraintPosition position) {
+            this.type = type;
+            this.kind = kind;
+            this.position = position;
+        }
+    }
 }
diff --git a/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/TypeBoundsImpl.java b/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/TypeBoundsImpl.java
index 3f278faeec5..20ef01fb9f0 100644
--- a/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/TypeBoundsImpl.java
+++ b/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/TypeBoundsImpl.java
@@ -31,23 +31,9 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.Set;
 
+import static org.jetbrains.jet.lang.resolve.calls.inference.TypeBounds.BoundKind.LOWER_BOUND;
+
 public class TypeBoundsImpl implements TypeBounds {
-    public static enum BoundKind {
-        LOWER_BOUND, UPPER_BOUND, EXACT_BOUND
-    }
-
-    public static class Bound {
-        public final JetType type;
-        public final BoundKind kind;
-        public final ConstraintPosition position;
-
-        public Bound(@NotNull JetType type, @NotNull BoundKind kind, @NotNull ConstraintPosition position) {
-            this.type = type;
-            this.kind = kind;
-            this.position = position;
-        }
-    }
-
     private final TypeParameterDescriptor typeVariable;
     private final Variance varianceOfPosition;
     private final Set<Bound> bounds = Sets.newLinkedHashSet();
@@ -78,6 +64,13 @@ public class TypeBoundsImpl implements TypeBounds {
         return getValues().isEmpty();
     }
 
+    @NotNull
+    @Override
+    public TypeParameterDescriptor getTypeVariable() {
+        return typeVariable;
+    }
+
+    @Override
     @NotNull
     public Collection<Bound> getBounds() {
         return bounds;
@@ -175,7 +168,7 @@ public class TypeBoundsImpl implements TypeBounds {
         values.addAll(exactBounds);
 
         Pair<Collection<JetType>, Collection<JetType>> pair =
-                TypeUtils.filterNumberTypes(filterBounds(bounds, BoundKind.LOWER_BOUND, values));
+                TypeUtils.filterNumberTypes(filterBounds(bounds, LOWER_BOUND, values));
         Collection<JetType> generalLowerBounds = pair.getFirst();
         Collection<JetType> numberLowerBounds = pair.getSecond();