let b, c, a be real number ; :: thesis: ( b < 0 & c < a * b implies a < c / b )
assume A1: ( b < 0 & a * b > c ) ; :: thesis: a < c / b
then (a * b) / b < c / b by Lm32;
hence a < c / b by A1, XCMPLX_1:90; :: thesis: verum