reserve a,b,c,d for Real;
reserve r,s for Real;

theorem
  b < 0 & -b <= a implies a/b <= -1
proof
  assume that
A1: b < 0 and
A2: -b <= a;
  assume a/b>-1;
  then a/b*b < (-1)*b by A1,Lm24;
  hence thesis by A1,A2,XCMPLX_1:87;
end;
