set cB1 = all-square-uparrow ;
set cB2 = [:base_of_frechet_filter,base_of_frechet_filter:];
A1: now :: thesis: for b1 being Element of all-square-uparrow ex b2 being Element of [:base_of_frechet_filter,base_of_frechet_filter:] st b2 c= b1end;
now :: thesis: for b2 being Element of [:base_of_frechet_filter,base_of_frechet_filter:] ex b1 being Element of all-square-uparrow st b1 c= b2end;
hence all-square-uparrow ,[:base_of_frechet_filter,base_of_frechet_filter:] are_equivalent_generators by A1; :: thesis: verum