diff --git a/README.md b/README.md
index 35192e5..2d57293 100644
--- a/README.md
+++ b/README.md
@@ -20,7 +20,7 @@ Listed in order of importance.
 
 - [ ] Backend
     - [ ] Core language
-        - [x] AST
+        - [ ] AST
     - [ ] Emitter
         - [ ] MSIL Codegen module
         - [ ] Core language emitter
diff --git a/rlp/Core.java b/rlp/Core.java
index 158176a..05bbaab 100644
--- a/rlp/Core.java
+++ b/rlp/Core.java
@@ -1,7 +1,5 @@
 package rlp;
 /*------------------------------------------------------------------------------*/
-import java.util.function.BiFunction;
-/*------------------------------------------------------------------------------*/
 
 public class Core
 {
@@ -13,10 +11,11 @@ public class Core
     public record TyAbs(Name n, Expr m)     implements Expr {}
     public record Var(Name n)               implements Expr {}
 
-    sealed interface Ty permits TyVar, Forall, TyFunc {}
-    public record TyVar(Name n)         implements Ty {}
-    public record Forall(Name n, Ty t)  implements Ty {}
-    public record TyFunc(Ty a, Ty b)    implements Ty {}
+    sealed interface Ty permits VarTy, Forall, FuncTy, AppTy {}
+    public record VarTy(Name n)         implements Ty {}
+    public record Forall(Name n, Ty m)  implements Ty {}
+    public record FuncTy(Ty a, Ty b)    implements Ty {}
+    public record AppTy(Ty f, Ty x)     implements Ty {}
 
     public final static class Name
     {
@@ -74,9 +73,14 @@ public class Core
     {
         return switch(t)
         {
-            case TyVar a   -> a.n.s;
-            case Forall a  -> "";
-            case TyFunc a  -> "";
+            case VarTy a ->
+                a.n.s;
+            case Forall a ->
+                wrap(p, 0, "∀" + a.n.s + "." + showTyP(0, a.m));
+            case FuncTy a ->
+                "";
+            case AppTy a ->
+                showTyP(2, a.f) + " " + showTyP(2, a.x);
         };
     }
 
diff --git a/rlp/RLPC.java b/rlp/RLPC.java
index a2db769..404aa99 100644
--- a/rlp/RLPC.java
+++ b/rlp/RLPC.java
@@ -12,7 +12,7 @@ class RLPC
 			new Core.App
 				( new Core.Abs
 					( new Core.Name("x")
-					, new Core.TyVar(new Core.Name("α"))
+					, new Core.VarTy(new Core.Name("α"))
 					, new Core.Var(new Core.Name("x"))
 					)
 				, new Core.Var(new Core.Name("y")));