diff -r 67d6dceb1002 -r e1439046d96e samples/visitor/21-clientprovider/src-api3.0/org/apidesign/visitor/Language.java
--- a/samples/visitor/21-clientprovider/src-api3.0/org/apidesign/visitor/Language.java	Sat Jun 14 09:59:20 2008 +0200
+++ b/samples/visitor/21-clientprovider/src-api3.0/org/apidesign/visitor/Language.java	Sun Oct 06 22:05:14 2013 +0200
@@ -29,12 +29,12 @@
         
         
         /** @since 3.0 */
-        public static Visitor create(Version3_0 v) {
-            return create3_0(v);
+        public static Visitor create(Version30 v) {
+            return create30(v);
         }
 
         /** @since 3.0 */
-        public interface Version3_0 {
+        public interface Version30 {
             public boolean visitUnknown(Expression e);
             public void visitPlus(Plus s);
             public void visitMinus(Minus s);
@@ -46,12 +46,12 @@
         
     // FINISH: visitor.clientprovider.v3
         /** @since 2.0 */
-        public static Visitor create(Version2_0 v) {
-            return create2_0(v);
+        public static Visitor create(Version20 v) {
+            return create20(v);
         }
 
         /** @since 2.0 */
-        public interface Version2_0 extends Version1_0 {
+        public interface Version20 extends Version10 {
             public void visitMinus(Minus m);
         }
 
@@ -59,11 +59,11 @@
         /** @since 2.0 */
         public abstract void dispatchNumber(Number n);
         
-        public static Visitor create(Version1_0 v) {
-            return create1_0(v);
+        public static Visitor create(Version10 v) {
+            return create10(v);
         }
 
-        public interface Version1_0 {
+        public interface Version10 {
             public boolean visitUnknown(Expression e);
             public void visitPlus(Plus s);
             public void visitNumber(Number n);
@@ -74,7 +74,7 @@
     }
     
     // BEGIN: visitor.clientprovider.dispatch.v3.l1
-    static Visitor create1_0(final Visitor.Version1_0 v) {
+    static Visitor create10(final Visitor.Version10 v) {
         return new Visitor() {
             @Override
             public void dispatchPlus(Plus p) {
@@ -102,7 +102,7 @@
     }
     // END: visitor.clientprovider.dispatch.v3.l1
     // BEGIN: visitor.clientprovider.dispatch.v3.l2
-    static Visitor create2_0(final Visitor.Version2_0 v) {
+    static Visitor create20(final Visitor.Version20 v) {
         return new Visitor() {
             @Override
             public void dispatchPlus(Plus p) {
@@ -127,7 +127,7 @@
     }
     // END: visitor.clientprovider.dispatch.v3.l2
     // BEGIN: visitor.clientprovider.dispatch.v3.l3
-    static Visitor create3_0(final Visitor.Version3_0 v) {
+    static Visitor create30(final Visitor.Version30 v) {
         return new Visitor() {
             @Override
             public void dispatchReal(Real r) {