--- a/string.rhope	Thu Dec 23 02:00:27 2010 +0000
+++ b/string.rhope	Thu Dec 23 15:48:19 2010 -0500
@@ -828,26 +828,50 @@
         }
 }
 
+Depth@String[string:out]
+{
+	out <- 0
+}
+
+Depth@String Slice[string:out]
+{
+	out <- 0
+}
+
+Depth@String Cat[string:out]
+{
+	out <- Depth >>[string]
+}
+
 Blueprint String Cat
 {
 	Left
 	Right
 	Length
 	ByteLen
+	Depth
 }
 
 String Cat[left,right:out]
 {
-	out <- [[[[Build[String Cat()]
+	out <- [[[[[Build[String Cat()]
 		]Left <<[left]
 		]Right <<[right]
 		]Length <<[ [[left]Length]+[[right]Length] ]
 		]ByteLen <<[ [[left]Byte Length]+[[right]Byte Length] ]
+		]Depth <<[ [1]+[Min[[left]Depth, [right]Depth]] ]
 }
 
 Append@String Cat[left,right:out]
 {
-	out <- String Cat[left,right]
+	ll <- [left]Left >>
+	lr <- [left]Right >>
+	If[[[ll]Depth] > [[lr]Depth]]
+	{
+		out <- String Cat[ll, String Cat[lr,right]]
+	}{
+		out <- String Cat[left,right]
+	}
 }
 
 Byte@String Cat[string,index:out,invalid]