diff --git a/sources/zweic/Tree.scala b/sources/zweic/Tree.scala
index 438783b..f081ed4 100755
--- a/sources/zweic/Tree.scala
+++ b/sources/zweic/Tree.scala
@@ -122,12 +122,35 @@
  */
 abstract class Expr extends Tree;
 
-// ... � compl�ter ...
+/* E = Ident name */
+case class Ident(name: Name) extends Expr;
 
-/**
- * E = Unop O E
- */
+/* E = New name { E } */
+case class New(name: Name, args: List[Expr]) extends Expr;
+
+/* E = Select E name */
+case class Select(varname: Expr, name: Name) extends Expr;
+
+/* E = Call E name { E } */
+case class Call(func: Expr, name: Name, args: List[Expr]) extends Expr;
+
+/* E = Unop O E */
 case class Unop(op: Operator, expr: Expr) extends Expr;
 
+/* E = Binop O E E */
+case class Binop(op: Operator, left: Expr, right: Expr) extends Expr;
+
+/* E = ReadInt */
+case class ReadInt extends Expr;
+
+/* E = ReadChar */
+case class ReadChar extends Expr;
+
+/* E = If E E E */
+case class If(cond: Expr, stata: Expr, statb: Expr) extends Expr;
+
+/* E = Block { S } E */
+case class Block(stats: List[Stat], expression: Expr) extends Expr;
+
 
 //############################################################################