+bool is_display_math_env(std::string const & name);
+char const * const * is_known(std::string const &, char const * const *);
+
+/*!
+ * Adds the command \p command to the list of known commands.
+ * \param o1 first optional parameter to the latex command \\newcommand
+ * (with brackets), or the empty string if there were no optional arguments.
+ * \param o2 wether \\newcommand had a second optional parameter.
+ * If \p definition is not empty the command is assumed to be from the LyX
+ * preamble and added to possible_textclass_commands.
+ */
+void add_known_command(std::string const & command, std::string const & o1,
+ bool o2, docstring const & definition = docstring());
+extern void add_known_environment(std::string const & environment,
+ std::string const & o1, bool o2, docstring const & beg,
+ docstring const & end);
+extern Layout const * findLayoutWithoutModule(TextClass const & textclass,
+ std::string const & name, bool command);
+extern InsetLayout const * findInsetLayoutWithoutModule(
+ TextClass const & textclass, std::string const & name, bool command);
+/*!
+ * Check whether a module provides command (if \p command is true) or
+ * environment (if \p command is false) \p name, and add the module to the
+ * list of used modules if yes.
+ */
+extern bool checkModule(std::string const & name, bool command);