reconsider S = (V * (the_Source_of G)) * (E ") as Function of (rng E),(rng V) by Lm1;
reconsider T = (V * (the_Target_of G)) * (E ") as Function of (rng E),(rng V) by Lm1;
take
createGraph ((rng V),(rng E),S,T)
; ex S, T being Function of (rng E),(rng V) st
( S = (V * (the_Source_of G)) * (E ") & T = (V * (the_Target_of G)) * (E ") & createGraph ((rng V),(rng E),S,T) = createGraph ((rng V),(rng E),S,T) )
take
S
; ex T being Function of (rng E),(rng V) st
( S = (V * (the_Source_of G)) * (E ") & T = (V * (the_Target_of G)) * (E ") & createGraph ((rng V),(rng E),S,T) = createGraph ((rng V),(rng E),S,T) )
take
T
; ( S = (V * (the_Source_of G)) * (E ") & T = (V * (the_Target_of G)) * (E ") & createGraph ((rng V),(rng E),S,T) = createGraph ((rng V),(rng E),S,T) )
thus
( S = (V * (the_Source_of G)) * (E ") & T = (V * (the_Target_of G)) * (E ") & createGraph ((rng V),(rng E),S,T) = createGraph ((rng V),(rng E),S,T) )
; verum