reserve i,j,k,k1,k2,i1,i2,j1,j2 for Nat,
  r,s for Real,
  x for set,
  f for non constant standard special_circular_sequence;

theorem Th2:
  for i,j st i<=len GoB f & j<=width GoB f holds Cl Down(Int cell(
  GoB f,i,j),(L~f)`)=cell(GoB f,i,j)/\((L~f)`)
proof
  let i,j;
  reconsider V=Int cell(GoB f,i,j) as Subset of TOP-REAL 2;
  reconsider B=(L~f)` as Subset of TOP-REAL 2;
  assume
A1: i<=len GoB f & j<=width GoB f;
  then Cl Down(V,B) =(Cl V) /\ B by Th1,CONNSP_3:29;
  hence thesis by A1,GOBRD11:35;
end;
