let G2 be _Graph; :: thesis: for E being set
for G1 being reverseEdgeDirections of G2,E
for W2 being Walk of G2 holds W2 is Walk of G1

let E be set ; :: thesis: for G1 being reverseEdgeDirections of G2,E
for W2 being Walk of G2 holds W2 is Walk of G1

let G1 be reverseEdgeDirections of G2,E; :: thesis: for W2 being Walk of G2 holds W2 is Walk of G1
let W2 be Walk of G2; :: thesis: W2 is Walk of G1
per cases ( E c= the_Edges_of G2 or not E c= the_Edges_of G2 ) ;
end;