+// realsymbol
+
+realsymbol::realsymbol(const std::string & initname, unsigned domain)
+ : symbol(initname, domain) { }
+
+realsymbol::realsymbol(const std::string & initname, const std::string & texname, unsigned domain)
+ : symbol(initname, texname, domain) { }
+
+realsymbol::realsymbol(const std::string & initname, unsigned rt, tinfo_t rtt, unsigned domain)
+ : symbol(initname, rt, rtt, domain) { }
+
+realsymbol::realsymbol(const std::string & initname, const std::string & texname, unsigned rt, tinfo_t rtt, unsigned domain)
+ : symbol(initname, texname, rt, rtt, domain) { }
+
+// possymbol
+
+possymbol::possymbol(const std::string & initname, unsigned domain)
+ : symbol(initname, domain) { }
+
+possymbol::possymbol(const std::string & initname, const std::string & texname, unsigned domain)
+ : symbol(initname, texname, domain) { }
+
+possymbol::possymbol(const std::string & initname, unsigned rt, tinfo_t rtt, unsigned domain)
+ : symbol(initname, rt, rtt, domain) { }
+
+possymbol::possymbol(const std::string & initname, const std::string & texname, unsigned rt, tinfo_t rtt, unsigned domain)
+ : symbol(initname, texname, rt, rtt, domain) { }
+
+//////////
+// archiving
+//////////
+
+/** Construct object from archive_node. */
+symbol::symbol(const archive_node &n, lst &sym_lst)
+ : inherited(n, sym_lst), serial(next_serial++)