+// Get name of symbol/index
+std::string get_symbol_name(const ex & s)
+{
+ if (is_a<symbol>(s))
+ return ex_to<symbol>(s).get_name();
+ else if (is_a<idx>(s) && is_a<symbol>(s.op(0)))
+ return ex_to<symbol>(s.op(0)).get_name();
+ else
+ throw (std::runtime_error("get_symbol_name(): unexpected expression type"));
+}
+
+// Set the list of predefined symbols/indices