let j be Nat; for p being Point of (TOP-REAL 2)
for G being Go-board st 1 <= j & j + 1 <= width G holds
LSeg (p,(((1 / 2) * ((G * ((len G),j)) + (G * ((len G),(j + 1))))) + |[1,0]|)) meets Int (cell (G,(len G),j))
let p be Point of (TOP-REAL 2); for G being Go-board st 1 <= j & j + 1 <= width G holds
LSeg (p,(((1 / 2) * ((G * ((len G),j)) + (G * ((len G),(j + 1))))) + |[1,0]|)) meets Int (cell (G,(len G),j))
let G be Go-board; ( 1 <= j & j + 1 <= width G implies LSeg (p,(((1 / 2) * ((G * ((len G),j)) + (G * ((len G),(j + 1))))) + |[1,0]|)) meets Int (cell (G,(len G),j)) )
assume A1:
( 1 <= j & j + 1 <= width G )
; LSeg (p,(((1 / 2) * ((G * ((len G),j)) + (G * ((len G),(j + 1))))) + |[1,0]|)) meets Int (cell (G,(len G),j))
now ex a being Element of the carrier of (TOP-REAL 2) st
( a in LSeg (p,(((1 / 2) * ((G * ((len G),j)) + (G * ((len G),(j + 1))))) + |[1,0]|)) & a in Int (cell (G,(len G),j)) )take a =
((1 / 2) * ((G * ((len G),j)) + (G * ((len G),(j + 1))))) + |[1,0]|;
( a in LSeg (p,(((1 / 2) * ((G * ((len G),j)) + (G * ((len G),(j + 1))))) + |[1,0]|)) & a in Int (cell (G,(len G),j)) )thus
a in LSeg (
p,
(((1 / 2) * ((G * ((len G),j)) + (G * ((len G),(j + 1))))) + |[1,0]|))
by RLTOPSP1:68;
a in Int (cell (G,(len G),j))thus
a in Int (cell (G,(len G),j))
by A1, Th34;
verum end;
hence
LSeg (p,(((1 / 2) * ((G * ((len G),j)) + (G * ((len G),(j + 1))))) + |[1,0]|)) meets Int (cell (G,(len G),j))
by XBOOLE_0:3; verum