	+ should be +=. Found by Clerk Ma, 5feb25.

--- teckit-2.5.13/source/Compiler.cpp	Tue Dec 16 22:47:30 2025
+++ TECkit-src/source/Compiler.cpp	Wed Dec 31 13:22:00 2025
@@ -708,7 +708,7 @@
 							if (currentRule.lhsPreContext.size() != 0) {
 								contextID = getContextID(currentRule.lhsPreContext, sourceUni);
 								xmlRule += " preCtx=\"";
-								xmlRule + contextID;
+								xmlRule += contextID;
 								xmlRule += "\"";
 							}
 							if (currentRule.lhsPostContext.size() != 0) {
