let G be _finite real-weighted WGraph; for EL being FF:ELabeling of G
for source, sink being set
for V being Subset of (the_Vertices_of G) st EL has_valid_flow_from source,sink & source in V & not sink in V holds
EL .flow (source,sink) <= Sum ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))
let EL be FF:ELabeling of G; for source, sink being set
for V being Subset of (the_Vertices_of G) st EL has_valid_flow_from source,sink & source in V & not sink in V holds
EL .flow (source,sink) <= Sum ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))
let source, sink be set ; for V being Subset of (the_Vertices_of G) st EL has_valid_flow_from source,sink & source in V & not sink in V holds
EL .flow (source,sink) <= Sum ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))
let V be Subset of (the_Vertices_of G); ( EL has_valid_flow_from source,sink & source in V & not sink in V implies EL .flow (source,sink) <= Sum ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) )
assume that
A1:
EL has_valid_flow_from source,sink
and
A2:
source in V
and
A3:
not sink in V
; EL .flow (source,sink) <= Sum ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))
set W1 = (the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V)));
set E2 = EL | (G .edgesDBetween (((the_Vertices_of G) \ V),V));
set E1 = EL | (G .edgesDBetween (V,((the_Vertices_of G) \ V)));
now for e being set st e in G .edgesDBetween (V,((the_Vertices_of G) \ V)) holds
(EL | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) . e <= ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) . elet e be
set ;
( e in G .edgesDBetween (V,((the_Vertices_of G) \ V)) implies (EL | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) . e <= ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) . e )assume A4:
e in G .edgesDBetween (
V,
((the_Vertices_of G) \ V))
;
(EL | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) . e <= ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) . ethen A5:
((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) . e = (the_Weight_of G) . e
by FUNCT_1:49;
(EL | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) . e = EL . e
by A4, FUNCT_1:49;
hence
(EL | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) . e <= ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) . e
by A1, A4, A5;
verum end;
then
Sum (EL | (G .edgesDBetween (V,((the_Vertices_of G) \ V)))) <= Sum ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))
by GLIB_004:5;
then A6:
(Sum (EL | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))) - (Sum (EL | (G .edgesDBetween (((the_Vertices_of G) \ V),V)))) <= (Sum ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))) - (Sum (EL | (G .edgesDBetween (((the_Vertices_of G) \ V),V))))
by XREAL_1:9;
set B1 = EmptyBag (G .edgesDBetween (((the_Vertices_of G) \ V),V));
A7:
now for e being set st e in G .edgesDBetween (((the_Vertices_of G) \ V),V) holds
(EmptyBag (G .edgesDBetween (((the_Vertices_of G) \ V),V))) . e <= (EL | (G .edgesDBetween (((the_Vertices_of G) \ V),V))) . elet e be
set ;
( e in G .edgesDBetween (((the_Vertices_of G) \ V),V) implies (EmptyBag (G .edgesDBetween (((the_Vertices_of G) \ V),V))) . e <= (EL | (G .edgesDBetween (((the_Vertices_of G) \ V),V))) . e )A8:
EmptyBag (G .edgesDBetween (((the_Vertices_of G) \ V),V)) = (G .edgesDBetween (((the_Vertices_of G) \ V),V)) --> 0
by PBOOLE:def 3;
assume
e in G .edgesDBetween (
((the_Vertices_of G) \ V),
V)
;
(EmptyBag (G .edgesDBetween (((the_Vertices_of G) \ V),V))) . e <= (EL | (G .edgesDBetween (((the_Vertices_of G) \ V),V))) . ehence
(EmptyBag (G .edgesDBetween (((the_Vertices_of G) \ V),V))) . e <= (EL | (G .edgesDBetween (((the_Vertices_of G) \ V),V))) . e
by A8, FUNCOP_1:7;
verum end;
Sum (EmptyBag (G .edgesDBetween (((the_Vertices_of G) \ V),V))) = 0
by UPROOTS:11;
then
0 <= Sum (EL | (G .edgesDBetween (((the_Vertices_of G) \ V),V)))
by A7, GLIB_004:5;
then A9:
(Sum ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))) - (Sum (EL | (G .edgesDBetween (((the_Vertices_of G) \ V),V)))) <= (Sum ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))) - 0
by XREAL_1:13;
EL .flow (source,sink) = (Sum (EL | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))) - (Sum (EL | (G .edgesDBetween (((the_Vertices_of G) \ V),V))))
by A1, A2, A3, Th11;
hence
EL .flow (source,sink) <= Sum ((the_Weight_of G) | (G .edgesDBetween (V,((the_Vertices_of G) \ V))))
by A9, A6, XXREAL_0:2; verum