def navigate(self, inst, kind, rel_id, phrase='<STR_LIT>'):
key = (kind.upper(), rel_id, phrase)<EOL>if key in self.links:<EOL><INDENT>link = self.links[key]<EOL>return link.navigate(inst)<EOL><DEDENT>link1, link2 = self._find_assoc_links(kind, rel_id, phrase)<EOL>inst_set = xtuml.OrderedSet()<EOL>for inst in link1.navigate(inst):<EOL><INDENT>inst_set |= link2.navigate(inst)<EOL><DEDENT>return inst_set<EOL>
Navigate across a link with some *rel_id* and *phrase* that yields
instances of some *kind*.