theorem Th15: :: GOBOARD7:15

for i, j being Nat
for G being Go-board st 1 <= i & i + 1 <= len G & 1 <= j & j + 1 <= width G holds
(LSeg ((G * (i,j)),(G * (i,(j + 1))))) /\ (LSeg ((G * (i,(j + 1))),(G * ((i + 1),(j + 1))))) = {(G * (i,(j + 1)))}