let i be Element of NAT ; :: thesis: for p being Point of (TOP-REAL 2)
for G being Go-board st 1 <= i & i + 1 <= len G holds
LSeg p,(((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|) meets Int (cell G,i,(width G))
let p be Point of (TOP-REAL 2); :: thesis: for G being Go-board st 1 <= i & i + 1 <= len G holds
LSeg p,(((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|) meets Int (cell G,i,(width G))
let G be Go-board; :: thesis: ( 1 <= i & i + 1 <= len G implies LSeg p,(((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|) meets Int (cell G,i,(width G)) )
assume A1:
( 1 <= i & i + 1 <= len G )
; :: thesis: LSeg p,(((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|) meets Int (cell G,i,(width G))
now take a =
((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|;
:: thesis: ( a in LSeg p,(((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|) & a in Int (cell G,i,(width G)) )thus
a in LSeg p,
(((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|)
by RLTOPSP1:69;
:: thesis: a in Int (cell G,i,(width G))thus
a in Int (cell G,i,(width G))
by A1, Th35;
:: thesis: verum end;
hence
LSeg p,(((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|) meets Int (cell G,i,(width G))
by XBOOLE_0:3; :: thesis: verum