for f, f1 being PartFunc of REAL,REAL st f1 is divergent_in-infty_to+infty & ex r being Real st
( left_open_halfline r c= (dom f) /\ (dom f1) & ( for g being Real st g in left_open_halfline r holds
f1 . g <= f . g ) ) holds
f is divergent_in-infty_to+infty