reserve X for set, x,y,z for object,
  k,l,n for Nat,
  r for Real;
reserve i,i0,i1,i2,i3,i4,i5,i8,i9,j for Integer;
reserve r1,p,p1,g,g1,g2 for Real,
  Y for Subset of REAL;
reserve r, s for Real;

theorem
  r/s is Integer implies - [\ r/s /] = [\ (-r) / s /]
proof
  assume r/s is Integer;
  then
A1: [\ r/s /] = r/s;
    -r/s = (-r)/s by XCMPLX_1:187;
  hence thesis by A1;
end;
