diff --git a/src/expresses.ts b/src/expresses.ts
index 5b9ed22..c66c0b9 100644
--- a/src/expresses.ts
+++ b/src/expresses.ts
@@ -1,7 +1,7 @@
-import { Call, Pipe, Tuples } from "hotscript"
+import { Call, ComposeLeft, Pipe, Tuples } from "hotscript"
 import { AbstractClass, Opaque } from "type-fest"
-import { Trait, TraitAbstractMembersFn, TraitApplierSuperTag, TraitClassFn, TraitImplClassFn, TraitImplInstanceFn, TraitInstanceFn } from "."
-import { ExtendFn, SimplifyFn, StaticMembersFn } from "./util"
+import { Trait, TraitAbstractMembersFn, TraitApplierSuperTag, TraitImplClassFn, TraitImplInstanceFn } from "."
+import { ExtendFn, ExtendableFn, SimplifyFn, StaticMembers, StaticMembersFn } from "./util"
 
 
 class TraitExpression<
@@ -42,33 +42,6 @@ class TraitExpression<
     }
 }
 
-type TraitExpressionOutput<Exp extends TraitExpression<any, any>> = (
-    Exp extends TraitExpression<infer Super, infer Traits>
-        ? (
-            AbstractClass<
-                Pipe<[
-                    InstanceType<Super>,
-                    ...Call<Tuples.Map<TraitInstanceFn>, Traits>,
-                ], [
-                    ExtendFn,
-                    SimplifyFn,
-                ]>,
-
-                ConstructorParameters<Super>
-            > &
-
-            Pipe<[
-                Super,
-                ...Call<Tuples.Map<TraitClassFn>, Traits>,
-            ], [
-                Tuples.Map<StaticMembersFn>,
-                ExtendFn,
-                SimplifyFn,
-            ]>
-        )
-        : never
-)
-
 export type Implements<Exp extends TraitExpression<any, any>> = (
     Exp extends TraitExpression<any, infer Traits>
         ? Pipe<Traits, [
@@ -80,14 +53,63 @@ export type Implements<Exp extends TraitExpression<any, any>> = (
 )
 
 
+type AbstractMembersExtendable<
+    Super  extends AbstractClass<any>,
+    Traits extends readonly Trait<any, any>[],
+> = (
+    Call<ExtendableFn, [
+        InstanceType<Super>,
+        ...Call<Tuples.Map<TraitAbstractMembersFn>, Traits>,
+    ]>
+)
+
+type ImplInstanceExtendable<
+    Super  extends AbstractClass<any>,
+    Traits extends readonly Trait<any, any>[],
+> = (
+    Call<ExtendableFn, [
+        InstanceType<Super>,
+        ...Call<Tuples.Map<TraitImplInstanceFn>, Traits>,
+    ]>
+)
+
+type ImplStaticMembersExtendable<
+    Super  extends AbstractClass<any>,
+    Traits extends readonly Trait<any, any>[],
+> = (
+    Call<ExtendableFn, [
+        StaticMembers<Super>,
+        ...Call<
+            Tuples.Map<
+                ComposeLeft<[TraitImplClassFn, StaticMembersFn]>
+            >,
+            Traits
+        >,
+    ]>
+)
+
+
+type ExtendsAndExpressesReturnType<
+    Super  extends AbstractClass<any>,
+    Traits extends readonly Trait<any, any>[],
+> = (
+    AbstractMembersExtendable<Super, Traits>   extends true ?
+    ImplInstanceExtendable<Super, Traits>      extends true ?
+    ImplStaticMembersExtendable<Super, Traits> extends true ?
+        TraitExpression<Super, Traits>
+    : "Type conflict between the traits implementation static members and/or the superclass static members."
+    : "Type conflict between the traits implementation instances and/or the superclass instance."
+    : "Type conflict between the traits abstract members and/or the superclass instance."
+)
+
 export function extendsAndExpresses<
     Super  extends AbstractClass<any>,
     Traits extends readonly Trait<any, any>[],
 >(
     superclass:  Super,
     ...traits:   Traits
-) {
-    return new TraitExpression(superclass, traits)
+): ExtendsAndExpressesReturnType<Super, Traits> {
+    return new TraitExpression(superclass, traits) as any
 }
 
 class DefaultSuperclass {}
@@ -96,6 +118,6 @@ export function expresses<
     Traits extends readonly Trait<any, any>[],
 >(
     ...traits: Traits
-) {
-    return new TraitExpression(DefaultSuperclass, traits)
+): ExtendsAndExpressesReturnType<typeof DefaultSuperclass, Traits> {
+    return new TraitExpression(DefaultSuperclass, traits) as any
 }
diff --git a/src/tests.ts b/src/tests.ts
index b5ca906..2555515 100644
--- a/src/tests.ts
+++ b/src/tests.ts
@@ -1,6 +1,4 @@
-import { Booleans, Call, Compose, ComposeLeft, Match, Pipe, Tuples } from "hotscript"
-import { Implements, TraitAbstractMembers, TraitAbstractMembersFn, expresses, extendsAndExpresses, trait } from "."
-import { CheckExtendableFn, ExtendFn, Extendable, ExtendableFn, SimplifyFn } from "./util"
+import { Implements, TraitAbstractMembers, extendsAndExpresses, trait } from "."
 
 
 const PrintsHelloOnNew = trait()(Super =>
@@ -45,7 +43,8 @@ const ActiveStatefulSubscription = trait<ActiveStatefulSubscriptionAbstractMembe
 
 
 class TestSuperclass {
-    id: number = 69
+    // id: number = 69
+    static test = 69
 }
 
 
@@ -54,11 +53,7 @@ const exp = extendsAndExpresses(
     Identifiable<bigint>(),
     // Identifiable<number>()
 )
-type ExpImpl = Implements<typeof exp>
-type ExpAbstractMembers = Pipe<typeof exp.traits, [
-    Tuples.Map<TraitAbstractMembersFn>,
-]>
-type ExpExtendable = Extendable<ExpAbstractMembers>
+// type ExpImpl = ImplStaticMembersExtendable<typeof TestSuperclass, typeof exp.traits>
 
 class User extends exp.extends() implements Implements<typeof exp> {
     id: bigint = -1n
diff --git a/src/trait.ts b/src/trait.ts
index a8b758e..df897c3 100644
--- a/src/trait.ts
+++ b/src/trait.ts
@@ -3,16 +3,16 @@ import { AbstractClass, Class, Opaque } from "type-fest"
 import { StaticMembers } from "./util"
 
 
-type AddAbstractMembersToImpl<
-    Impl            extends Class<object, []>,
-    AbstractMembers extends object,
-> = (
-    Class<
-        InstanceType<Impl> & AbstractMembers,
-        ConstructorParameters<Impl>
-    > &
-    StaticMembers<Impl>
-)
+// type AddAbstractMembersToImpl<
+//     Impl            extends Class<object, []>,
+//     AbstractMembers extends object,
+// > = (
+//     Class<
+//         InstanceType<Impl> & AbstractMembers,
+//         ConstructorParameters<Impl>
+//     > &
+//     StaticMembers<Impl>
+// )
 
 type RemoveAbstractMembersFromImplInstance<
     ImplInstanceWithAbstractMembers extends AbstractMembers,
@@ -21,7 +21,7 @@ type RemoveAbstractMembersFromImplInstance<
     Omit<ImplInstanceWithAbstractMembers, keyof AbstractMembers>
 )
 
-type RemoveAbstractMembersFromImpl<
+type RemoveAbstractMembersFromImplClass<
     ImplWithAbstractMembers extends Class<AbstractMembers, []>,
     AbstractMembers         extends object,
 > = (
@@ -63,7 +63,7 @@ export interface TraitAbstractMembersFn extends Fn {
 
 export type TraitImplClass<T> = (
     T extends Trait<infer AbstractMembers, infer ImplWithAbstractMembers>
-        ? RemoveAbstractMembersFromImpl<
+        ? RemoveAbstractMembersFromImplClass<
             ImplWithAbstractMembers,
             AbstractMembers
         >