SCM internal_get_property (SCM name_sym) const;
SCM properties_as_alist () const;
Context *where_defined (SCM name_sym, SCM *value) const;
+ bool here_defined (SCM name_sym, SCM *value) const;
void unset_property (SCM var_sym);
void instrumented_set_property (SCM, SCM, const char *, int, const char *);