diff --git a/idea/src/org/jetbrains/jet/lang/modules/MemberDomain.java b/idea/src/org/jetbrains/jet/lang/modules/MemberDomain.java
deleted file mode 100644
index 14182a867a3..00000000000
--- a/idea/src/org/jetbrains/jet/lang/modules/MemberDomain.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package org.jetbrains.jet.lang.modules;
-
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.jetbrains.jet.lang.types.ClassDescriptor;
-import org.jetbrains.jet.lang.types.ExtensionDescriptor;
-import org.jetbrains.jet.lang.types.MethodDescriptor;
-import org.jetbrains.jet.lang.types.PropertyDescriptor;
-
-import java.util.Collection;
-
-/**
- * @author abreslav
- */
-public interface MemberDomain {
-    @NotNull
-    Collection<MethodDescriptor> getMethods(String name);
-
-    @Nullable
-    ClassDescriptor getClass(String name);
-
-    @Nullable
-    PropertyDescriptor getProperty(String name);
-
-    @Nullable
-    ExtensionDescriptor getExtension(String name);
-}
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/ClassDescriptorResolver.java b/idea/src/org/jetbrains/jet/lang/resolve/ClassDescriptorResolver.java
index 4c53ae66617..d4451ef9de1 100644
--- a/idea/src/org/jetbrains/jet/lang/resolve/ClassDescriptorResolver.java
+++ b/idea/src/org/jetbrains/jet/lang/resolve/ClassDescriptorResolver.java
@@ -30,75 +30,44 @@ public class ClassDescriptorResolver {
                 ? Collections.singleton(JetStandardClasses.getAnyType())
                 : resolveTypes(typeParameterScope, delegationSpecifiers);
         boolean open = classElement.hasModifier(JetTokens.OPEN_KEYWORD);
+        WritableScope members = resolveMembers(classElement, typeParameters, scope, typeParameterScope, superclasses);
+
         return new ClassDescriptor(
                 AttributeResolver.INSTANCE.resolveAttributes(classElement.getModifierList()),
                 !open,
                 classElement.getName(),
                 typeParameters,
                 superclasses,
-                resolveMemberDomain(classElement, scope, typeParameterScope, superclasses)
+                members
         );
     }
 
-    private TypeMemberDomain resolveMemberDomain(
+    private WritableScope resolveMembers(
             final JetClass classElement,
+            List<TypeParameterDescriptor> typeParameters,
             final JetScope outerScope,
             final TypeParameterExtensibleScope typeParameterScope,
             final Collection<? extends Type> supertypes) {
-        // TODO : Cache!!!
-        return new TypeMemberDomain() {
-            @Override
-            public PropertyDescriptor getProperty(Type contextType, @NotNull String name) {
-                // TODO : primary constructor parameters
-                List<JetDeclaration> declarations = classElement.getDeclarations();
-                for (JetDeclaration declaration : declarations) {
-                    if (!name.equals(declaration.getName())) {
-                        continue;
-                    }
-                    if (declaration instanceof JetProperty) {
-                        JetProperty property = (JetProperty) declaration;
 
-                        if (property.getPropertyTypeRef() != null) {
-                            return substituteInPropertyDescriptor(contextType, resolvePropertyDescriptor(typeParameterScope, property));
-                        } else {
-                            // TODO : Caution: a cyclic dependency possible
-                            throw new UnsupportedOperationException();
-                        }
-                    }
+        WritableScope memberDeclarations = new WritableScope();
+
+        List<JetDeclaration> declarations = classElement.getDeclarations();
+        for (JetDeclaration declaration : declarations) {
+            if (declaration instanceof JetProperty) {
+                JetProperty property = (JetProperty) declaration;
+
+                if (property.getPropertyTypeRef() != null) {
+                    memberDeclarations.addPropertyDescriptor(resolvePropertyDescriptor(typeParameterScope, property));
+                } else {
+                    // TODO : Caution: a cyclic dependency possible
+                    throw new UnsupportedOperationException();
                 }
-
-                for (Type supertype : supertypes) {
-                    PropertyDescriptor property = supertype.getMemberDomain().getProperty(JetTypeChecker.INSTANCE.substitute(contextType, supertype, Variance.INVARIANT), name);
-                    if (property != null) {
-                        return property;
-                    }
-                }
-                return null;
-            }
-
-            @Override
-            public ClassDescriptor getClassDescriptor(@NotNull Type contextType, String name) {
+            } else {
                 throw new UnsupportedOperationException(); // TODO
             }
-
-            @NotNull
-            @Override
-            public Collection<MethodDescriptor> getMethods(Type contextType, String name) {
-                throw new UnsupportedOperationException(); // TODO
-            }
-
-            @Override
-            public ExtensionDescriptor getExtension(Type contextType, String name) {
-                throw new UnsupportedOperationException(); // TODO
-            }
-        };
-    }
-
-    private PropertyDescriptor substituteInPropertyDescriptor(Type contextType, PropertyDescriptor propertyDescriptor) {
-        if (contextType.getConstructor().getParameters().isEmpty()) {
-            return propertyDescriptor;
         }
-        return new LazySubstitutedPropertyDescriptorImpl(propertyDescriptor, contextType);
+
+        return memberDeclarations;
     }
 
     private static List<TypeParameterDescriptor> resolveTypeParameters(TypeParameterExtensibleScope extensibleScope, List<JetTypeParameter> typeParameters) {
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/JetScope.java b/idea/src/org/jetbrains/jet/lang/resolve/JetScope.java
index 817e6a65e53..8acc3da532e 100644
--- a/idea/src/org/jetbrains/jet/lang/resolve/JetScope.java
+++ b/idea/src/org/jetbrains/jet/lang/resolve/JetScope.java
@@ -2,16 +2,31 @@ package org.jetbrains.jet.lang.resolve;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.jetbrains.jet.lang.modules.MemberDomain;
-import org.jetbrains.jet.lang.modules.NamespaceDomain;
 import org.jetbrains.jet.lang.types.*;
 
+import java.util.Collection;
+
 /**
  * @author abreslav
  */
-public interface JetScope extends NamespaceDomain, MemberDomain {
+public interface JetScope {
     JetScope EMPTY = new JetScopeImpl() {};
 
+    @NotNull
+    Collection<MethodDescriptor> getMethods(String name);
+
+    @Nullable
+    ClassDescriptor getClass(String name);
+
+    @Nullable
+    PropertyDescriptor getProperty(String name);
+
+    @Nullable
+    ExtensionDescriptor getExtension(String name);
+
+    @Nullable
+    NamespaceDescriptor getNamespace(String name);
+
     @Nullable
     TypeParameterDescriptor getTypeParameterDescriptor(String name);
 
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/ScopeWithReceiver.java b/idea/src/org/jetbrains/jet/lang/resolve/ScopeWithReceiver.java
index 5f014ffb3a7..9372d623c92 100644
--- a/idea/src/org/jetbrains/jet/lang/resolve/ScopeWithReceiver.java
+++ b/idea/src/org/jetbrains/jet/lang/resolve/ScopeWithReceiver.java
@@ -15,7 +15,7 @@ public class ScopeWithReceiver extends JetScopeImpl {
 
     public ScopeWithReceiver(JetScope outerScope, Type receiverType) {
         this.outerScope = outerScope;
-        this.receiverTypeScope = new TypeScope(receiverType);
+        this.receiverTypeScope = receiverType.getMemberScope();
     }
 
     @Override
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/SubstitutingScope.java b/idea/src/org/jetbrains/jet/lang/resolve/SubstitutingScope.java
new file mode 100644
index 00000000000..3614a312af9
--- /dev/null
+++ b/idea/src/org/jetbrains/jet/lang/resolve/SubstitutingScope.java
@@ -0,0 +1,62 @@
+package org.jetbrains.jet.lang.resolve;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.types.*;
+
+import java.util.Collection;
+import java.util.Map;
+
+/**
+ * @author abreslav
+ */
+public class SubstitutingScope implements JetScope {
+
+    private final JetScope workerScope;
+    private final Map<TypeConstructor, TypeProjection> substitutionContext;
+
+    public SubstitutingScope(JetScope workerScope, Map<TypeConstructor, TypeProjection> substitutionContext) {
+        this.workerScope = workerScope;
+        this.substitutionContext = substitutionContext;
+    }
+
+    @Override
+    public PropertyDescriptor getProperty(String name) {
+        PropertyDescriptor property = workerScope.getProperty(name);
+        if (property == null) {
+            return null;
+        }
+        return new LazySubstitutedPropertyDescriptorImpl(property, substitutionContext);
+    }
+
+    @NotNull
+    @Override
+    public Collection<MethodDescriptor> getMethods(String name) {
+        throw new UnsupportedOperationException(); // TODO
+    }
+
+    @Override
+    public ClassDescriptor getClass(String name) {
+        throw new UnsupportedOperationException(); // TODO
+    }
+
+    @Override
+    public ExtensionDescriptor getExtension(String name) {
+        throw new UnsupportedOperationException(); // TODO
+    }
+
+    @Override
+    public NamespaceDescriptor getNamespace(String name) {
+        throw new UnsupportedOperationException(); // TODO
+    }
+
+    @Override
+    public TypeParameterDescriptor getTypeParameterDescriptor(String name) {
+        throw new UnsupportedOperationException(); // TODO
+    }
+
+    @NotNull
+    @Override
+    public Type getThisType() {
+        throw new UnsupportedOperationException(); // TODO
+    }
+}
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/TypeResolver.java b/idea/src/org/jetbrains/jet/lang/resolve/TypeResolver.java
index 13a5a7fbb68..a3a90993788 100644
--- a/idea/src/org/jetbrains/jet/lang/resolve/TypeResolver.java
+++ b/idea/src/org/jetbrains/jet/lang/resolve/TypeResolver.java
@@ -36,12 +36,13 @@ public class TypeResolver {
                 ClassDescriptor classDescriptor = resolveClass(scope, type);
                 if (classDescriptor != null) {
                     TypeConstructor typeConstructor = classDescriptor.getTypeConstructor();
+                    List<TypeProjection> arguments = resolveTypeProjections(scope, typeConstructor, type.getTypeArguments());
                     result[0] = new TypeImpl(
                             attributes,
                             typeConstructor,
                             nullable,
-                            resolveTypeProjections(scope, typeConstructor, type.getTypeArguments()),
-                            classDescriptor.getMemberDomain()
+                            arguments,
+                            classDescriptor.getMemberScope(arguments)
                     );
                 }
                 else if (type.getTypeArguments().isEmpty()) {
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/TypeScope.java b/idea/src/org/jetbrains/jet/lang/resolve/TypeScope.java
deleted file mode 100644
index e1830370c48..00000000000
--- a/idea/src/org/jetbrains/jet/lang/resolve/TypeScope.java
+++ /dev/null
@@ -1,53 +0,0 @@
-package org.jetbrains.jet.lang.resolve;
-
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.jet.lang.types.*;
-
-import java.util.Collection;
-
-/**
- * @author abreslav
- */
-public class TypeScope implements JetScope {
-    private final Type receiverType;
-
-    public TypeScope(Type receiverType) {
-        this.receiverType = receiverType;
-    }
-
-    @Override
-    public TypeParameterDescriptor getTypeParameterDescriptor(String name) {
-        return null;
-    }
-
-    @NotNull
-    @Override
-    public Type getThisType() {
-        return receiverType;
-    }
-
-    @Override
-    public Collection<MethodDescriptor> getMethods(String name) {
-        return receiverType.getMemberDomain().getMethods(receiverType, name);
-    }
-
-    @Override
-    public ClassDescriptor getClass(String name) {
-        return receiverType.getMemberDomain().getClassDescriptor(receiverType, name);
-    }
-
-    @Override
-    public PropertyDescriptor getProperty(String name) {
-        return receiverType.getMemberDomain().getProperty(receiverType, name);
-    }
-
-    @Override
-    public ExtensionDescriptor getExtension(String name) {
-        return receiverType.getMemberDomain().getExtension(receiverType, name);
-    }
-
-    @Override
-    public NamespaceDescriptor getNamespace(String name) {
-        return null;
-    }
-}
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/WritableScope.java b/idea/src/org/jetbrains/jet/lang/resolve/WritableScope.java
new file mode 100644
index 00000000000..6416995ddc7
--- /dev/null
+++ b/idea/src/org/jetbrains/jet/lang/resolve/WritableScope.java
@@ -0,0 +1,60 @@
+package org.jetbrains.jet.lang.resolve;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.types.*;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * @author abreslav
+ */
+public class WritableScope implements JetScope {
+    private Map<String, PropertyDescriptor> propertyDescriptors;
+
+    public void addPropertyDescriptor(PropertyDescriptor propertyDescriptor) {
+        if (propertyDescriptors == null) {
+            propertyDescriptors = new HashMap<String, PropertyDescriptor>();
+        }
+        assert !propertyDescriptors.containsKey(propertyDescriptor.getName()) : "Property redeclared";
+        propertyDescriptors.put(propertyDescriptor.getName(), propertyDescriptor);
+    }
+
+    @Override
+    public PropertyDescriptor getProperty(String name) {
+        return propertyDescriptors.get(name);
+    }
+
+    @NotNull
+    @Override
+    public Collection<MethodDescriptor> getMethods(String name) {
+        throw new UnsupportedOperationException(); // TODO
+    }
+
+    @Override
+    public ClassDescriptor getClass(String name) {
+        throw new UnsupportedOperationException(); // TODO
+    }
+
+    @Override
+    public ExtensionDescriptor getExtension(String name) {
+        throw new UnsupportedOperationException(); // TODO
+    }
+
+    @Override
+    public NamespaceDescriptor getNamespace(String name) {
+        throw new UnsupportedOperationException(); // TODO
+    }
+
+    @Override
+    public TypeParameterDescriptor getTypeParameterDescriptor(String name) {
+        throw new UnsupportedOperationException(); // TODO
+    }
+
+    @NotNull
+    @Override
+    public Type getThisType() {
+        throw new UnsupportedOperationException(); // TODO
+    }
+}
diff --git a/idea/src/org/jetbrains/jet/lang/types/ClassDescriptor.java b/idea/src/org/jetbrains/jet/lang/types/ClassDescriptor.java
index 075db373af7..da0a9bc1fed 100644
--- a/idea/src/org/jetbrains/jet/lang/types/ClassDescriptor.java
+++ b/idea/src/org/jetbrains/jet/lang/types/ClassDescriptor.java
@@ -1,31 +1,34 @@
 package org.jetbrains.jet.lang.types;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.resolve.JetScope;
+import org.jetbrains.jet.lang.resolve.SubstitutingScope;
 
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 
 /**
  * @author abreslav
  */
 public class ClassDescriptor extends MemberDescriptorImpl {
     private final TypeConstructor typeConstructor;
-    private final TypeMemberDomain memberDomain;
+    private final JetScope memberDeclarations;
 
     public ClassDescriptor(
             List<Attribute> attributes, boolean sealed,
             String name, List<TypeParameterDescriptor> typeParameters,
-            Collection<? extends Type> superclasses, TypeMemberDomain memberDomain) {
+            Collection<? extends Type> superclasses, JetScope memberDeclarations) {
         super(attributes, name);
         this.typeConstructor = new TypeConstructor(attributes, sealed, name, typeParameters, superclasses);
-        this.memberDomain = memberDomain;
+        this.memberDeclarations = memberDeclarations;
     }
 
-    public ClassDescriptor(String name, TypeMemberDomain memberDomain) {
+    public ClassDescriptor(String name, JetScope memberDeclarations) {
         this(Collections.<Attribute>emptyList(), true,
                 name, Collections.<TypeParameterDescriptor>emptyList(),
-                Collections.<Type>singleton(JetStandardClasses.getAnyType()), memberDomain);
+                Collections.<Type>singleton(JetStandardClasses.getAnyType()), memberDeclarations);
     }
 
     @NotNull
@@ -33,12 +36,8 @@ public class ClassDescriptor extends MemberDescriptorImpl {
         return typeConstructor;
     }
 
-    public TypeMemberDomain getMemberDomain() {
-        return memberDomain;
+    public JetScope getMemberScope(List<TypeProjection> typeArguments) {
+        Map<TypeConstructor,TypeProjection> substitutionContext = TypeSubstitutor.INSTANCE.buildSubstitutionContext(typeConstructor.getParameters(), typeArguments);
+        return new SubstitutingScope(memberDeclarations, substitutionContext);
     }
-
-    public ClassDescriptor getClass(String referencedName) {
-        throw new UnsupportedOperationException(); // TODO
-    }
-
 }
\ No newline at end of file
diff --git a/idea/src/org/jetbrains/jet/lang/types/ErrorType.java b/idea/src/org/jetbrains/jet/lang/types/ErrorType.java
index 4777883b2c5..f9e894051b8 100644
--- a/idea/src/org/jetbrains/jet/lang/types/ErrorType.java
+++ b/idea/src/org/jetbrains/jet/lang/types/ErrorType.java
@@ -1,6 +1,7 @@
 package org.jetbrains.jet.lang.types;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.resolve.JetScope;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -10,25 +11,41 @@ import java.util.List;
  * @author abreslav
  */
 public class ErrorType {
-    private static final TypeMemberDomain ERROR_DOMAIN = new TypeMemberDomain() {
+    private static final JetScope ERROR_SCOPE = new JetScope() {
+        @NotNull
         @Override
-        public ClassDescriptor getClassDescriptor(@NotNull Type contextType, String name) {
+        public Collection<MethodDescriptor> getMethods(String name) {
+            throw new UnsupportedOperationException(); // TODO
+        }
+
+        @Override
+        public ClassDescriptor getClass(String name) {
+            throw new UnsupportedOperationException(); // TODO
+        }
+
+        @Override
+        public PropertyDescriptor getProperty(String name) {
+            throw new UnsupportedOperationException(); // TODO
+        }
+
+        @Override
+        public ExtensionDescriptor getExtension(String name) {
+            throw new UnsupportedOperationException(); // TODO
+        }
+
+        @Override
+        public NamespaceDescriptor getNamespace(String name) {
+            throw new UnsupportedOperationException(); // TODO
+        }
+
+        @Override
+        public TypeParameterDescriptor getTypeParameterDescriptor(String name) {
             throw new UnsupportedOperationException(); // TODO
         }
 
         @NotNull
         @Override
-        public Collection<MethodDescriptor> getMethods(Type contextType, String name) {
-            throw new UnsupportedOperationException(); // TODO
-        }
-
-        @Override
-        public PropertyDescriptor getProperty(Type contextType, String name) {
-            throw new UnsupportedOperationException(); // TODO
-        }
-
-        @Override
-        public ExtensionDescriptor getExtension(Type contextType, String name) {
+        public Type getThisType() {
             throw new UnsupportedOperationException(); // TODO
         }
     };
@@ -36,15 +53,15 @@ public class ErrorType {
     private ErrorType() {}
 
     public static Type createErrorType(String debugMessage) {
-        return createErrorType(debugMessage, ERROR_DOMAIN);
+        return createErrorType(debugMessage, ERROR_SCOPE);
     }
 
-    private static Type createErrorType(String debugMessage, TypeMemberDomain memberDomain) {
-        return new ErrorTypeImpl(new TypeConstructor(Collections.<Attribute>emptyList(), false, "[ERROR : " + debugMessage + "]", Collections.<TypeParameterDescriptor>emptyList(), Collections.<Type>emptyList()), memberDomain);
+    private static Type createErrorType(String debugMessage, JetScope memberScope) {
+        return new ErrorTypeImpl(new TypeConstructor(Collections.<Attribute>emptyList(), false, "[ERROR : " + debugMessage + "]", Collections.<TypeParameterDescriptor>emptyList(), Collections.<Type>emptyList()), memberScope);
     }
 
     public static Type createWrongVarianceErrorType(TypeProjection value) {
-        return createErrorType(value + " is not allowed here]", value.getType().getMemberDomain());
+        return createErrorType(value + " is not allowed here]", value.getType().getMemberScope());
     }
 
     public static boolean isErrorType(Type type) {
@@ -54,11 +71,11 @@ public class ErrorType {
     private static class ErrorTypeImpl implements Type {
 
         private final TypeConstructor constructor;
-        private final TypeMemberDomain memberDomain;
+        private final JetScope memberScope;
 
-        private ErrorTypeImpl(TypeConstructor constructor, TypeMemberDomain memberDomain) {
+        private ErrorTypeImpl(TypeConstructor constructor, JetScope memberScope) {
             this.constructor = constructor;
-            this.memberDomain = memberDomain;
+            this.memberScope = memberScope;
         }
 
         @NotNull
@@ -80,8 +97,8 @@ public class ErrorType {
 
         @NotNull
         @Override
-        public TypeMemberDomain getMemberDomain() {
-            return memberDomain;
+        public JetScope getMemberScope() {
+            return memberScope;
         }
 
         @Override
diff --git a/idea/src/org/jetbrains/jet/lang/types/JetStandardClasses.java b/idea/src/org/jetbrains/jet/lang/types/JetStandardClasses.java
index f562fbdb8a7..21456a606c7 100644
--- a/idea/src/org/jetbrains/jet/lang/types/JetStandardClasses.java
+++ b/idea/src/org/jetbrains/jet/lang/types/JetStandardClasses.java
@@ -4,6 +4,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.resolve.JetScope;
 import org.jetbrains.jet.lang.resolve.JetScopeImpl;
+import org.jetbrains.jet.lang.resolve.WritableScope;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
@@ -34,7 +35,7 @@ public class JetStandardClasses {
                 public int size() {
                     throw new UnsupportedOperationException();
                 }
-            }, TypeMemberDomain.EMPTY
+            }, JetScope.EMPTY
     );
 
     private static final ClassDescriptor ANY = new ClassDescriptor(
@@ -43,33 +44,12 @@ public class JetStandardClasses {
             "Any",
             Collections.<TypeParameterDescriptor>emptyList(),
             Collections.<Type>emptySet(),
-            TypeMemberDomain.EMPTY
+            JetScope.EMPTY
     );
 
-    public static final TypeMemberDomain STUB = new TypeMemberDomain() {
-        @Override
-        public ClassDescriptor getClassDescriptor(@NotNull Type contextType, String name) {
-            throw new UnsupportedOperationException(); // TODO
-        }
+    public static final JetScope STUB = JetScope.EMPTY;
 
-        @NotNull
-        @Override
-        public Collection<MethodDescriptor> getMethods(Type contextType, String name) {
-            throw new UnsupportedOperationException(); // TODO
-        }
-
-        @Override
-        public PropertyDescriptor getProperty(Type contextType, String name) {
-            throw new UnsupportedOperationException(); // TODO
-        }
-
-        @Override
-        public ExtensionDescriptor getExtension(Type contextType, String name) {
-            throw new UnsupportedOperationException(); // TODO
-        }
-    };
-
-    private static final Type ANY_TYPE = new TypeImpl(ANY.getTypeConstructor(), TypeMemberDomain.EMPTY);
+    private static final Type ANY_TYPE = new TypeImpl(ANY.getTypeConstructor(), JetScope.EMPTY);
 
     private static final Type NULLABLE_ANY_TYPE = TypeUtils.makeNullable(ANY_TYPE);
     private static final ClassDescriptor BYTE    = new ClassDescriptor("Byte", STUB);
@@ -157,7 +137,7 @@ public class JetStandardClasses {
             getNothing().getTypeConstructor(),
             true,
             Collections.<TypeProjection>emptyList(),
-            TypeMemberDomain.EMPTY);
+            JetScope.EMPTY);
 
     private static final Map<String, ClassDescriptor> CLASS_MAP = new HashMap<String, ClassDescriptor>();
     static {
diff --git a/idea/src/org/jetbrains/jet/lang/types/JetTypeChecker.java b/idea/src/org/jetbrains/jet/lang/types/JetTypeChecker.java
index 967017d547f..e71d70feaf4 100644
--- a/idea/src/org/jetbrains/jet/lang/types/JetTypeChecker.java
+++ b/idea/src/org/jetbrains/jet/lang/types/JetTypeChecker.java
@@ -233,9 +233,10 @@ public class JetTypeChecker {
                     JetUserType typeElement = (JetUserType) superTypeQualifier.getTypeElement();
                     ClassDescriptor superclass = TypeResolver.INSTANCE.resolveClass(scope, typeElement);
                     Collection<? extends Type> supertypes = thisType.getConstructor().getSupertypes();
+                    Map<TypeConstructor, TypeProjection> substitutionContext = TypeSubstitutor.INSTANCE.getSubstitutionContext(thisType);
                     for (Type declaredSupertype : supertypes) {
                         if (declaredSupertype.getConstructor().equals(superclass.getTypeConstructor())) {
-                            result[0] = substituteInType(getSubstitutionContext(thisType), declaredSupertype, Variance.INVARIANT);
+                            result[0] = TypeSubstitutor.INSTANCE.substitute(substitutionContext, declaredSupertype, Variance.INVARIANT);
                             break;
                         }
                     }
@@ -515,13 +516,13 @@ public class JetTypeChecker {
             return;
         }
         handler.beforeChildren(current);
-        Map<TypeConstructor, TypeProjection> substitutionContext = getSubstitutionContext(current);
+        Map<TypeConstructor, TypeProjection> substitutionContext = TypeSubstitutor.INSTANCE.getSubstitutionContext(current);
         for (Type supertype : current.getConstructor().getSupertypes()) {
             TypeConstructor supertypeConstructor = supertype.getConstructor();
             if (visited.contains(supertypeConstructor)) {
                 continue;
             }
-            Type substitutedSupertype = substituteInType(substitutionContext, supertype, Variance.INVARIANT);
+            Type substitutedSupertype = TypeSubstitutor.INSTANCE.substitute(substitutionContext, supertype, Variance.INVARIANT);
             dfs(substitutedSupertype, visited, handler);
         }
         handler.afterChildren(current);
@@ -557,67 +558,12 @@ public class JetTypeChecker {
         for (Type immediateSupertype : constructor.getSupertypes()) {
             Type correspondingSupertype = findCorrespondingSupertype(immediateSupertype, supertype);
             if (correspondingSupertype != null) {
-                return substituteInType(getSubstitutionContext(subtype), correspondingSupertype, Variance.INVARIANT);
+                return TypeSubstitutor.INSTANCE.substitute(subtype, correspondingSupertype, Variance.INVARIANT);
             }
         }
         return null;
     }
 
-    private Map<TypeConstructor, TypeProjection> getSubstitutionContext(Type context) {
-        Map<TypeConstructor, TypeProjection> parameterValues = new HashMap<TypeConstructor, TypeProjection>();
-
-        List<TypeParameterDescriptor> parameters = context.getConstructor().getParameters();
-        List<TypeProjection> contextArguments = context.getArguments();
-        for (int i = 0, parametersSize = parameters.size(); i < parametersSize; i++) {
-            TypeParameterDescriptor parameter = parameters.get(i);
-            TypeProjection value = contextArguments.get(i);
-            parameterValues.put(parameter.getTypeConstructor(), value);
-        }
-        return parameterValues;
-    }
-
-    private Type substituteInType(Map<TypeConstructor, TypeProjection> substitutionContext, Type type, Variance howThisTypeIsUsed) {
-        TypeProjection value = substitutionContext.get(type.getConstructor());
-        if (value != null) {
-            Variance projectionKind = value.getProjectionKind();
-            if (howThisTypeIsUsed.allowsInPosition() && !projectionKind.allowsInPosition()
-                    || howThisTypeIsUsed.allowsOutPosition() && !projectionKind.allowsOutPosition()) {
-                return ErrorType.createWrongVarianceErrorType(value);
-            }
-            return value.getType();
-        }
-
-        return specializeType(type, substituteInArguments(substitutionContext, type));
-    }
-
-    @NotNull
-    private TypeProjection substitute(Map<TypeConstructor, TypeProjection> parameterValues, TypeProjection subject) {
-        @NotNull Type subjectType = subject.getType();
-        TypeProjection value = parameterValues.get(subjectType.getConstructor());
-        if (value != null) {
-            return value;
-        }
-        List<TypeProjection> newArguments = substituteInArguments(parameterValues, subjectType);
-        return new TypeProjection(subject.getProjectionKind(), specializeType(subjectType, newArguments));
-    }
-
-    private List<TypeProjection> substituteInArguments(Map<TypeConstructor, TypeProjection> parameterValues, Type subjectType) {
-        List<TypeProjection> newArguments = new ArrayList<TypeProjection>();
-        for (TypeProjection argument : subjectType.getArguments()) {
-            newArguments.add(substitute(parameterValues, argument));
-        }
-        return newArguments;
-    }
-
-    @NotNull
-    public Type substitute(@NotNull Type context, @NotNull Type subject, @NotNull Variance howThisTypeIsUsed) {
-        return substituteInType(getSubstitutionContext(context), subject, howThisTypeIsUsed);
-    }
-
-    private Type specializeType(Type type, List<TypeProjection> newArguments) {
-        return new TypeImpl(type.getAttributes(), type.getConstructor(), type.isNullable(), newArguments, type.getMemberDomain());
-    }
-
     private boolean checkSubtypeForTheSameConstructor(Type subtype, Type supertype) {
         TypeConstructor constructor = subtype.getConstructor();
         assert constructor.equals(supertype.getConstructor());
@@ -636,7 +582,7 @@ public class JetTypeChecker {
                 case INVARIANT:
                     switch (superArgument.getProjectionKind()) {
                         case INVARIANT:
-                            if (!equalTypes(subArgumentType, superArgumentType)) {
+                            if (!TypeImpl.equalTypes(subArgumentType, superArgumentType)) {
                                 return false;
                             }
                             break;
@@ -688,9 +634,4 @@ public class JetTypeChecker {
         }
         return true;
     }
-
-    public boolean equalTypes(@NotNull Type type1, @NotNull Type type2) {
-        return TypeImpl.equalTypes(type1, type2);
-    }
-
 }
\ No newline at end of file
diff --git a/idea/src/org/jetbrains/jet/lang/types/LazySubstitutedPropertyDescriptorImpl.java b/idea/src/org/jetbrains/jet/lang/types/LazySubstitutedPropertyDescriptorImpl.java
index 9a6aceea415..233c3567015 100644
--- a/idea/src/org/jetbrains/jet/lang/types/LazySubstitutedPropertyDescriptorImpl.java
+++ b/idea/src/org/jetbrains/jet/lang/types/LazySubstitutedPropertyDescriptorImpl.java
@@ -1,24 +1,27 @@
 package org.jetbrains.jet.lang.types;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.util.List;
+import java.util.Map;
 
 /**
  * @author abreslav
  */
 public class LazySubstitutedPropertyDescriptorImpl implements PropertyDescriptor {
     private final PropertyDescriptor propertyDescriptor;
-    private final Type contextType;
+    private final Map<TypeConstructor, TypeProjection> substitutionContext;
     private Type propertyType = null;
 
-    public LazySubstitutedPropertyDescriptorImpl(PropertyDescriptor propertyDescriptor, Type contextType) {
+    public LazySubstitutedPropertyDescriptorImpl(@NotNull PropertyDescriptor propertyDescriptor, @NotNull Map<TypeConstructor, TypeProjection> substitutionContext) {
         this.propertyDescriptor = propertyDescriptor;
-        this.contextType = contextType;
+        this.substitutionContext = substitutionContext;
     }
 
     @Override
     public Type getType() {
         if (propertyType == null) {
-            propertyType = JetTypeChecker.INSTANCE.substitute(contextType, propertyDescriptor.getType(), Variance.OUT_VARIANCE);
+            propertyType = TypeSubstitutor.INSTANCE.substitute(substitutionContext, propertyDescriptor.getType(), Variance.OUT_VARIANCE);
         }
         return propertyType;
     }
diff --git a/idea/src/org/jetbrains/jet/lang/types/NamespaceDescriptor.java b/idea/src/org/jetbrains/jet/lang/types/NamespaceDescriptor.java
index d95c984cf1b..999531558d6 100644
--- a/idea/src/org/jetbrains/jet/lang/types/NamespaceDescriptor.java
+++ b/idea/src/org/jetbrains/jet/lang/types/NamespaceDescriptor.java
@@ -1,6 +1,5 @@
 package org.jetbrains.jet.lang.types;
 
-import org.jetbrains.jet.lang.modules.MemberDomain;
 import org.jetbrains.jet.lang.modules.NamespaceDomain;
 
 import java.util.Collection;
@@ -8,23 +7,19 @@ import java.util.Collection;
 /**
  * @author abreslav
  */
-public class NamespaceDescriptor implements NamespaceDomain, MemberDomain {
-    @Override
+public class NamespaceDescriptor implements NamespaceDomain {
     public ClassDescriptor getClass(String name) {
         throw new UnsupportedOperationException(); // TODO
     }
 
-    @Override
     public Collection<MethodDescriptor> getMethods(String name) {
         throw new UnsupportedOperationException(); // TODO
     }
 
-    @Override
     public PropertyDescriptor getProperty(String name) {
         throw new UnsupportedOperationException(); // TODO
     }
 
-    @Override
     public ExtensionDescriptor getExtension(String name) {
         throw new UnsupportedOperationException(); // TODO
     }
diff --git a/idea/src/org/jetbrains/jet/lang/types/Type.java b/idea/src/org/jetbrains/jet/lang/types/Type.java
index a8af560c0f2..c3139bac462 100644
--- a/idea/src/org/jetbrains/jet/lang/types/Type.java
+++ b/idea/src/org/jetbrains/jet/lang/types/Type.java
@@ -1,6 +1,7 @@
 package org.jetbrains.jet.lang.types;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.resolve.JetScope;
 
 import java.util.List;
 
@@ -12,5 +13,6 @@ public interface Type extends Annotated {
     @NotNull List<TypeProjection> getArguments();
     boolean isNullable();
 
-    @NotNull TypeMemberDomain getMemberDomain();
+    @NotNull
+    JetScope getMemberScope();
 }
diff --git a/idea/src/org/jetbrains/jet/lang/types/TypeImpl.java b/idea/src/org/jetbrains/jet/lang/types/TypeImpl.java
index d44ad6a1f78..ff6eb8ef297 100644
--- a/idea/src/org/jetbrains/jet/lang/types/TypeImpl.java
+++ b/idea/src/org/jetbrains/jet/lang/types/TypeImpl.java
@@ -1,6 +1,7 @@
 package org.jetbrains.jet.lang.types;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.resolve.JetScope;
 
 import java.util.Collections;
 import java.util.Iterator;
@@ -14,18 +15,18 @@ public final class TypeImpl extends AnnotatedImpl implements Type {
     private final TypeConstructor constructor;
     private final List<TypeProjection> arguments;
     private final boolean nullable;
-    private final TypeMemberDomain memberDomain;
+    private JetScope memberScope;
 
-    public TypeImpl(List<Attribute> attributes, TypeConstructor constructor, boolean nullable, List<TypeProjection> arguments, TypeMemberDomain memberDomain) {
+    public TypeImpl(List<Attribute> attributes, TypeConstructor constructor, boolean nullable, List<TypeProjection> arguments, JetScope memberScope) {
         super(attributes);
         this.constructor = constructor;
         this.nullable = nullable;
         this.arguments = arguments;
-        this.memberDomain = memberDomain;
+        this.memberScope = memberScope;
     }
 
-    public TypeImpl(TypeConstructor constructor, TypeMemberDomain memberDomain) {
-        this(Collections.<Attribute>emptyList(), constructor, false, Collections.<TypeProjection>emptyList(), memberDomain);
+    public TypeImpl(TypeConstructor constructor, JetScope memberScope) {
+        this(Collections.<Attribute>emptyList(), constructor, false, Collections.<TypeProjection>emptyList(), memberScope);
     }
 
     public TypeImpl(ClassDescriptor classDescriptor) {
@@ -33,7 +34,7 @@ public final class TypeImpl extends AnnotatedImpl implements Type {
                 classDescriptor.getTypeConstructor(),
                 false,
                 Collections.<TypeProjection>emptyList(),
-                classDescriptor.getMemberDomain());
+                classDescriptor.getMemberScope(Collections.<TypeProjection>emptyList()));
     }
 
     @Override
@@ -52,8 +53,11 @@ public final class TypeImpl extends AnnotatedImpl implements Type {
     }
 
     @Override
-    public TypeMemberDomain getMemberDomain() {
-        return memberDomain;
+    public JetScope getMemberScope() {
+        if (memberScope == null) {
+            // TODO
+        }
+        return memberScope;
     }
 
     @Override
@@ -85,7 +89,7 @@ public final class TypeImpl extends AnnotatedImpl implements Type {
 //        if (nullable != type.nullable) return false;
 //        if (arguments != null ? !arguments.equals(type.arguments) : type.arguments != null) return false;
 //        if (constructor != null ? !constructor.equals(type.constructor) : type.constructor != null) return false;
-//        if (memberDomain != null ? !memberDomain.equals(type.memberDomain) : type.memberDomain != null) return false;
+//        if (memberScope != null ? !memberScope.equals(type.memberScope) : type.memberScope != null) return false;
 
 //        return true;
     }
diff --git a/idea/src/org/jetbrains/jet/lang/types/TypeMemberDomain.java b/idea/src/org/jetbrains/jet/lang/types/TypeMemberDomain.java
deleted file mode 100644
index 27150105664..00000000000
--- a/idea/src/org/jetbrains/jet/lang/types/TypeMemberDomain.java
+++ /dev/null
@@ -1,47 +0,0 @@
-package org.jetbrains.jet.lang.types;
-
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.Collection;
-import java.util.Collections;
-
-/**
- * @author abreslav
- */
-public interface TypeMemberDomain {
-    TypeMemberDomain EMPTY = new TypeMemberDomain() {
-        @Override
-        public ClassDescriptor getClassDescriptor(@NotNull Type contextType, String name) {
-            return null;
-        }
-
-        @NotNull
-        @Override
-        public Collection<MethodDescriptor> getMethods(Type contextType, String name) {
-            return Collections.emptyList();
-        }
-
-        @Override
-        public PropertyDescriptor getProperty(Type contextType, String name) {
-            return null;
-        }
-
-        @Override
-        public ExtensionDescriptor getExtension(Type contextType, String name) {
-            return null;
-        }
-    };
-
-    @Nullable
-    ClassDescriptor getClassDescriptor(@NotNull Type contextType, String name);
-
-    @NotNull
-    Collection<MethodDescriptor> getMethods(Type contextType, String name);
-
-    @Nullable
-    PropertyDescriptor getProperty(Type contextType, String name);
-
-    @Nullable
-    ExtensionDescriptor getExtension(Type contextType, String name);
-}
diff --git a/idea/src/org/jetbrains/jet/lang/types/TypeSubstitutor.java b/idea/src/org/jetbrains/jet/lang/types/TypeSubstitutor.java
new file mode 100644
index 00000000000..d6bacbd1e2d
--- /dev/null
+++ b/idea/src/org/jetbrains/jet/lang/types/TypeSubstitutor.java
@@ -0,0 +1,76 @@
+package org.jetbrains.jet.lang.types;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * @author abreslav
+ */
+public class TypeSubstitutor {
+    public static final TypeSubstitutor INSTANCE = new TypeSubstitutor();
+
+    private TypeSubstitutor() {}
+
+    public Type substitute(@NotNull Type context, @NotNull Type subject, @NotNull Variance howThisTypeIsUsed) {
+        return substitute(getSubstitutionContext(context), subject, howThisTypeIsUsed);
+    }
+
+    @NotNull
+    public Type substitute(@NotNull Map<TypeConstructor, TypeProjection> substitutionContext, @NotNull Type type, @NotNull Variance howThisTypeIsUsed) {
+        TypeProjection value = substitutionContext.get(type.getConstructor());
+        if (value != null) {
+            Variance projectionKind = value.getProjectionKind();
+            if (howThisTypeIsUsed.allowsInPosition() && !projectionKind.allowsInPosition()
+                    || howThisTypeIsUsed.allowsOutPosition() && !projectionKind.allowsOutPosition()) {
+                return ErrorType.createWrongVarianceErrorType(value);
+            }
+            return value.getType();
+        }
+
+        return specializeType(type, substituteInArguments(substitutionContext, type));
+    }
+
+    public Map<TypeConstructor, TypeProjection> getSubstitutionContext(Type context) {
+        List<TypeParameterDescriptor> parameters = context.getConstructor().getParameters();
+        List<TypeProjection> contextArguments = context.getArguments();
+
+        return buildSubstitutionContext(parameters, contextArguments);
+    }
+
+    public Map<TypeConstructor, TypeProjection> buildSubstitutionContext(List<TypeParameterDescriptor> parameters, List<TypeProjection> contextArguments) {
+        Map<TypeConstructor, TypeProjection> parameterValues = new HashMap<TypeConstructor, TypeProjection>();
+        for (int i = 0, parametersSize = parameters.size(); i < parametersSize; i++) {
+            TypeParameterDescriptor parameter = parameters.get(i);
+            TypeProjection value = contextArguments.get(i);
+            parameterValues.put(parameter.getTypeConstructor(), value);
+        }
+        return parameterValues;
+    }
+
+    @NotNull
+    private TypeProjection substituteInProjection(Map<TypeConstructor, TypeProjection> parameterValues, TypeProjection subject) {
+        @NotNull Type subjectType = subject.getType();
+        TypeProjection value = parameterValues.get(subjectType.getConstructor());
+        if (value != null) {
+            return value;
+        }
+        List<TypeProjection> newArguments = substituteInArguments(parameterValues, subjectType);
+        return new TypeProjection(subject.getProjectionKind(), specializeType(subjectType, newArguments));
+    }
+
+    private List<TypeProjection> substituteInArguments(Map<TypeConstructor, TypeProjection> parameterValues, Type subjectType) {
+        List<TypeProjection> newArguments = new ArrayList<TypeProjection>();
+        for (TypeProjection argument : subjectType.getArguments()) {
+            newArguments.add(substituteInProjection(parameterValues, argument));
+        }
+        return newArguments;
+    }
+
+    private Type specializeType(Type type, List<TypeProjection> newArguments) {
+        return new TypeImpl(type.getAttributes(), type.getConstructor(), type.isNullable(), newArguments, type.getMemberScope());
+    }
+}
diff --git a/idea/src/org/jetbrains/jet/lang/types/TypeUtils.java b/idea/src/org/jetbrains/jet/lang/types/TypeUtils.java
index 1ebddf4cde6..b8c5fd13e36 100644
--- a/idea/src/org/jetbrains/jet/lang/types/TypeUtils.java
+++ b/idea/src/org/jetbrains/jet/lang/types/TypeUtils.java
@@ -15,7 +15,7 @@ public class TypeUtils {
         if (type.isNullable()) {
             return type;
         }
-        return new TypeImpl(type.getAttributes(), type.getConstructor(), true, type.getArguments(), type.getMemberDomain());
+        return new TypeImpl(type.getAttributes(), type.getConstructor(), true, type.getArguments(), type.getMemberScope());
     }
 
     @Nullable
diff --git a/idea/tests/org/jetbrains/jet/types/JetTypeCheckerTest.java b/idea/tests/org/jetbrains/jet/types/JetTypeCheckerTest.java
index 38d7b56fddf..8f9a6e5f1ad 100644
--- a/idea/tests/org/jetbrains/jet/types/JetTypeCheckerTest.java
+++ b/idea/tests/org/jetbrains/jet/types/JetTypeCheckerTest.java
@@ -335,7 +335,7 @@ public class JetTypeCheckerTest extends LightDaemonAnalyzerTestCase {
             subtypes.add(makeType(type));
         }
         Type result = JetTypeChecker.INSTANCE.commonSupertype(subtypes);
-        assertTrue(result + " != " + expected, JetTypeChecker.INSTANCE.equalTypes(result, makeType(expected)));
+        assertTrue(result + " != " + expected, TypeImpl.equalTypes(result, makeType(expected)));
     }
 
     private static void assertSubtypingRelation(String type1, String type2, boolean expected) {
@@ -366,7 +366,7 @@ public class JetTypeCheckerTest extends LightDaemonAnalyzerTestCase {
         Project project = getProject();
         JetExpression jetExpression = JetChangeUtil.createExpression(project, expression);
         Type type = JetTypeChecker.INSTANCE.getType(ClassDefinitions.BASIC_SCOPE, jetExpression, false);
-        assertTrue(type + " != " + expectedType, JetTypeChecker.INSTANCE.equalTypes(type, expectedType));
+        assertTrue(type + " != " + expectedType, TypeImpl.equalTypes(type, expectedType));
     }
 
     private void assertErrorType(String expression) {
@@ -397,7 +397,7 @@ public class JetTypeCheckerTest extends LightDaemonAnalyzerTestCase {
         JetExpression jetExpression = JetChangeUtil.createExpression(project, expression);
         Type type = JetTypeChecker.INSTANCE.getType(scope, jetExpression, false);
         Type expectedType = makeType(expectedTypeStr);
-        assertTrue(type + " != " + expectedType, JetTypeChecker.INSTANCE.equalTypes(type, expectedType));
+        assertTrue(type + " != " + expectedType, TypeImpl.equalTypes(type, expectedType));
     }
 
     private static Type makeType(String typeStr) {