let G be real-weighted WGraph; :: thesis: for EL being FF:ELabeling of
for W being Walk of G st W is trivial holds
W is_augmenting_wrt EL
let EL be FF:ELabeling of ; :: thesis: for W being Walk of G st W is trivial holds
W is_augmenting_wrt EL
let W be Walk of G; :: thesis: ( W is trivial implies W is_augmenting_wrt EL )
assume A1:
W is trivial
; :: thesis: W is_augmenting_wrt EL
now let n be
odd Nat;
:: thesis: ( n < len W implies ( ( W . (n + 1) DJoins W . n,W . (n + 2),G implies EL . (W . (n + 1)) < (the_Weight_of G) . (W . (n + 1)) ) & ( not W . (n + 1) DJoins W . n,W . (n + 2),G implies 0 < EL . (W . (n + 1)) ) ) )assume
n < len W
;
:: thesis: ( ( W . (n + 1) DJoins W . n,W . (n + 2),G implies EL . (W . (n + 1)) < (the_Weight_of G) . (W . (n + 1)) ) & ( not W . (n + 1) DJoins W . n,W . (n + 2),G implies 0 < EL . (W . (n + 1)) ) )then
n < 1
by A1, GLIB_001:127;
hence
( (
W . (n + 1) DJoins W . n,
W . (n + 2),
G implies
EL . (W . (n + 1)) < (the_Weight_of G) . (W . (n + 1)) ) & ( not
W . (n + 1) DJoins W . n,
W . (n + 2),
G implies
0 < EL . (W . (n + 1)) ) )
by HEYTING3:1;
:: thesis: verum end;
hence
W is_augmenting_wrt EL
by Def12; :: thesis: verum