diff --git a/src/org/jetbrains/jet/j2k/ast/ArrayAccessExpression.kt b/src/org/jetbrains/jet/j2k/ast/ArrayAccessExpression.kt
deleted file mode 100644
index ae5913a512a..00000000000
--- a/src/org/jetbrains/jet/j2k/ast/ArrayAccessExpression.kt
+++ /dev/null
@@ -1,7 +0,0 @@
-package org.jetbrains.jet.j2k.ast
-
-public open class ArrayAccessExpression(val expression : Expression, val index : Expression) : Expression() {
-    public override fun toKotlin() : String {
-        return expression.toKotlin() + "[" + index.toKotlin() + "]"
-    }
-}
diff --git a/src/org/jetbrains/jet/j2k/ast/AssignmentExpression.kt b/src/org/jetbrains/jet/j2k/ast/AssignmentExpression.kt
deleted file mode 100644
index d23bd782875..00000000000
--- a/src/org/jetbrains/jet/j2k/ast/AssignmentExpression.kt
+++ /dev/null
@@ -1,6 +0,0 @@
-package org.jetbrains.jet.j2k.ast
-
-
-public open class AssignmentExpression(val left : Expression, val right : Expression, val op : String) : Expression() {
-    public override fun toKotlin() : String = left.toKotlin() + " "+ op + " "+ right.toKotlin()
-}
diff --git a/src/org/jetbrains/jet/j2k/ast/BangBangExpression.kt b/src/org/jetbrains/jet/j2k/ast/BangBangExpression.kt
deleted file mode 100644
index bc2cc371c58..00000000000
--- a/src/org/jetbrains/jet/j2k/ast/BangBangExpression.kt
+++ /dev/null
@@ -1,5 +0,0 @@
-package org.jetbrains.jet.j2k.ast
-
-public class BangBangExpression(val expr: Expression): Expression() {
-    public override fun toKotlin(): String = expr.toKotlin() + "!!"
-}
diff --git a/src/org/jetbrains/jet/j2k/ast/BinaryExpression.kt b/src/org/jetbrains/jet/j2k/ast/BinaryExpression.kt
deleted file mode 100644
index f7bef5e47c1..00000000000
--- a/src/org/jetbrains/jet/j2k/ast/BinaryExpression.kt
+++ /dev/null
@@ -1,8 +0,0 @@
-package org.jetbrains.jet.j2k.ast
-
-import java.util.Arrays
-import java.util.List
-
-public open class BinaryExpression(val left: Expression, val right: Expression, val op: String): Expression() {
-    public override fun toKotlin(): String = left.toKotlin() + " " + op + " " + right.toKotlin()
-}
diff --git a/src/org/jetbrains/jet/j2k/ast/ClassObjectAccessExpression.kt b/src/org/jetbrains/jet/j2k/ast/ClassObjectAccessExpression.kt
deleted file mode 100644
index fa3dbd0c3cf..00000000000
--- a/src/org/jetbrains/jet/j2k/ast/ClassObjectAccessExpression.kt
+++ /dev/null
@@ -1,8 +0,0 @@
-package org.jetbrains.jet.j2k.ast
-
-
-public open class ClassObjectAccessExpression(val typeElement: Element): Expression() {
-    public override fun toKotlin(): String {
-        return "getJavaClass<" + typeElement.toKotlin() + ">"
-    }
-}
diff --git a/src/org/jetbrains/jet/j2k/ast/Expressions.kt b/src/org/jetbrains/jet/j2k/ast/Expressions.kt
new file mode 100644
index 00000000000..b3e597c5e5e
--- /dev/null
+++ b/src/org/jetbrains/jet/j2k/ast/Expressions.kt
@@ -0,0 +1,30 @@
+package org.jetbrains.jet.j2k.ast
+
+public open class ArrayAccessExpression(val expression : Expression, val index : Expression) : Expression() {
+    override fun toKotlin() = expression.toKotlin() + "[" + index.toKotlin() + "]"
+    override fun isNullable() = expression.isNullable()
+}
+
+public open class AssignmentExpression(val left : Expression, val right : Expression, val op : String) : Expression() {
+    override fun toKotlin() = left.toKotlin() + " "+ op + " "+ right.toKotlin()
+}
+
+public class BangBangExpression(val expr: Expression): Expression() {
+    override fun toKotlin() = expr.toKotlin() + "!!"
+}
+
+public open class BinaryExpression(val left: Expression, val right: Expression, val op: String): Expression() {
+    override fun toKotlin() = left.toKotlin() + " " + op + " " + right.toKotlin()
+}
+
+public open class ClassObjectAccessExpression(val typeElement: Element): Expression() {
+    override fun toKotlin() = "getJavaClass<" + typeElement.toKotlin() + ">"
+}
+
+public open class IsOperator(val expression: Expression, val typeElement: TypeElement): Expression() {
+    override fun toKotlin() = expression.toKotlin() + " is " + typeElement.`type`.convertedToNotNull().toKotlin()
+}
+
+public open class LiteralExpression(val literalText: String): Expression() {
+    override fun toKotlin() = literalText
+}
diff --git a/src/org/jetbrains/jet/j2k/ast/IsOperator.kt b/src/org/jetbrains/jet/j2k/ast/IsOperator.kt
deleted file mode 100644
index cb853651339..00000000000
--- a/src/org/jetbrains/jet/j2k/ast/IsOperator.kt
+++ /dev/null
@@ -1,8 +0,0 @@
-package org.jetbrains.jet.j2k.ast
-
-
-public open class IsOperator(val expression: Expression, val typeElement: TypeElement): Expression() {
-    public override fun toKotlin(): String {
-        return expression.toKotlin() + " is " + typeElement.`type`.convertedToNotNull().toKotlin()
-    }
-}
diff --git a/src/org/jetbrains/jet/j2k/ast/LiteralExpression.kt b/src/org/jetbrains/jet/j2k/ast/LiteralExpression.kt
deleted file mode 100644
index 711fd2288bf..00000000000
--- a/src/org/jetbrains/jet/j2k/ast/LiteralExpression.kt
+++ /dev/null
@@ -1,6 +0,0 @@
-package org.jetbrains.jet.j2k.ast
-
-
-public open class LiteralExpression(val literalText: String): Expression() {
-    public override fun toKotlin() = literalText
-}