for eps being Real st 0 < eps holds
for d being Real st 0 < d holds
ex r1, r2 being Real st
( r1 in DYADIC \/ (right_open_halfline 1) & r2 in DYADIC \/ (right_open_halfline 1) & 0 < r1 & r1 < d & d < r2 & r2 - r1 < eps )