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

theorem
  b < 0 & -a <= b implies a/b <= -1
proof
  assume that
A1: b < 0 and
A2: -a <= b;
  assume a/b > -1;
  then a/b*b < (-1)*b by A1,Lm24;
  then a < -b by A1,XCMPLX_1:87;
  hence thesis by A2,Th26;
end;
