:: deftheorem Def2 defines h_strip GOBOARD5:def 2 :
for G being Matrix of (TOP-REAL 2)
for i being Nat holds
( ( 1 <= i & i < width G implies h_strip (G,i) = { |[r,s]| where r, s is Real : ( (G * (1,i)) `2 <= s & s <= (G * (1,(i + 1))) `2 ) } ) & ( i >= width G implies h_strip (G,i) = { |[r,s]| where r, s is Real : (G * (1,i)) `2 <= s } ) & ( ( not 1 <= i or not i < width G ) & not i >= width G implies h_strip (G,i) = { |[r,s]| where r, s is Real : s <= (G * (1,(i + 1))) `2 } ) );