diff -r 2415912b0aa0 -r f9a059c24aea stage3/narrow_candidate_datatypes.hh
--- a/stage3/narrow_candidate_datatypes.hh	Thu Aug 22 16:51:22 2013 +0100
+++ b/stage3/narrow_candidate_datatypes.hh	Thu Aug 22 16:53:17 2013 +0100
@@ -182,6 +182,7 @@
     /*********************/
     /* B 1.4 - Variables */
     /*********************/
+    void *visit(symbolic_variable_c *symbol);
     /********************************************/
     /* B 1.4.1 - Directly Represented Variables */
     /********************************************/