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

theorem
  b < 0 & -a < b implies a/b < -1
proof
  assume
A1: b < 0;
  assume
A2: -a < b;
  assume a/b >= -1;
  then a/b*b <= (-1)*b by A1,Lm28;
  then a <= -b by A1,XCMPLX_1:87;
  hence thesis by A2,Th25;
end;
