| 1 | 27. s1: traversal(the_graph) 28. s3: traversal(the_graph) 29. s = (s3 @ s1) traversal(the_graph) 30. paren(Vertices(the_graph);s1) 31. paren(Vertices(the_graph);s3) 32. j:Vertices(the_graph). (inl(j) s1)  L1-the_graph- > *j 33. j:Vertices(the_graph). (inl(j) s3)  nil-the_graph- > *j & L1-the_graph- > *j i:Vertices(the_graph). (inl(i) s)  L1-the_graph- > *i | 12 steps |