i:Vertices(G), s1,s2:traversal(G). s = (s1 @ [inr(i)] @ s2) 
traversal(G) 
(j:Vertices(G). (inr(j) s2) 
(inl(j) s2) j-G- > *i)) & (i:Vertices(G), s1,s2:traversal(G). (j:Vertices(G). i-G- > *j non-trivial-loop(G;j)) s = (s1 @ [inl(i)] @ s2) traversal(G) (j:Vertices(G). i-G- > *j (inr(j) s2)))
is mentioned
In prior sections: graph 1 2 graph 1 3