1 | 1. the_graph: Graph 2. L: Vertices(the_graph) List 3. i: Vertices(the_graph) 4. s: traversal(the_graph) 5. j:Vertices(the_graph). (inr(j) s)  (inl(j) s)  j-the_graph- > *i 6. L-the_graph- > *i 7. i:Vertices(the_graph), s1,s2:traversal(the_graph).
s = (s1 @ [inr(i)] @ s2) traversal(the_graph)

( j:Vertices(the_graph). (inr(j) s2)  (inl(j) s2)  j-the_graph- > *i) 8. j:Vertices(the_graph). (inr(j) s)  L-the_graph- > *j 9. i:Vertices(the_graph), s1,s2:traversal(the_graph).
( j:Vertices(the_graph). i-the_graph- > *j  non-trivial-loop(the_graph;j))

s = (s1 @ [inl(i)] @ s2) traversal(the_graph)  L-the_graph- > *i 10. i@0: Vertices(the_graph) 11. s1: traversal(the_graph) 12. s2: traversal(the_graph) 13. [inr(i) / s] = (s1 @ [inr(i@0)] @ s2) traversal(the_graph) 14. j: Vertices(the_graph) 15. (inr(j) s2) 16. (inl(j) s2) j-the_graph- > *i@0 | 5 steps |
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2 | 1. the_graph: Graph 2. L: Vertices(the_graph) List 3. i: Vertices(the_graph) 4. s: traversal(the_graph) 5. j:Vertices(the_graph). (inr(j) s)  (inl(j) s)  j-the_graph- > *i 6. L-the_graph- > *i 7. i:Vertices(the_graph), s1,s2:traversal(the_graph).
s = (s1 @ [inr(i)] @ s2) traversal(the_graph)

( j:Vertices(the_graph). (inr(j) s2)  (inl(j) s2)  j-the_graph- > *i) 8. j:Vertices(the_graph). (inr(j) s)  L-the_graph- > *j 9. i:Vertices(the_graph), s1,s2:traversal(the_graph).
( j:Vertices(the_graph). i-the_graph- > *j  non-trivial-loop(the_graph;j))

s = (s1 @ [inl(i)] @ s2) traversal(the_graph)  L-the_graph- > *i 10. j: Vertices(the_graph) 11. (inr(j) [inr(i) / s]) L-the_graph- > *j | 2 steps |
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3 | 1. the_graph: Graph 2. L: Vertices(the_graph) List 3. i: Vertices(the_graph) 4. s: traversal(the_graph) 5. j:Vertices(the_graph). (inr(j) s)  (inl(j) s)  j-the_graph- > *i 6. L-the_graph- > *i 7. i:Vertices(the_graph), s1,s2:traversal(the_graph).
s = (s1 @ [inr(i)] @ s2) traversal(the_graph)

( j:Vertices(the_graph). (inr(j) s2)  (inl(j) s2)  j-the_graph- > *i) 8. j:Vertices(the_graph). (inr(j) s)  L-the_graph- > *j 9. i:Vertices(the_graph), s1,s2:traversal(the_graph).
( j:Vertices(the_graph). i-the_graph- > *j  non-trivial-loop(the_graph;j))

s = (s1 @ [inl(i)] @ s2) traversal(the_graph)  L-the_graph- > *i 10. i@0: Vertices(the_graph) 11. s1: traversal(the_graph) 12. s2: traversal(the_graph) 13. j:Vertices(the_graph). i@0-the_graph- > *j  non-trivial-loop(the_graph;j) 14. [inr(i) / s] = (s1 @ [inl(i@0)] @ s2) traversal(the_graph) L-the_graph- > *i@0 | 3 steps |