let p be Point of (TOP-REAL 2); :: thesis: for G being Go-board holds LSeg p,((G * 1,1) - |[1,1]|) meets Int (cell G,0 ,0 )
let G be Go-board; :: thesis: LSeg p,((G * 1,1) - |[1,1]|) meets Int (cell G,0 ,0 )
now
take a = (G * 1,1) - |[1,1]|; :: thesis: ( a in LSeg p,((G * 1,1) - |[1,1]|) & a in Int (cell G,0 ,0 ) )
thus a in LSeg p,((G * 1,1) - |[1,1]|) by RLTOPSP1:69; :: thesis: a in Int (cell G,0 ,0 )
thus a in Int (cell G,0 ,0 ) by Th39; :: thesis: verum
end;
hence LSeg p,((G * 1,1) - |[1,1]|) meets Int (cell G,0 ,0 ) by XBOOLE_0:3; :: thesis: verum