Description: Lemma for prmrec . Here we show the inequality N / 2 < # M by decomposing the set ( 1 ... N ) into the disjoint union of the set M of those numbers that are not divisible by any "large" primes (above K ) and the indexed union over K < k of the numbers Wk that divide the prime k . By prmreclem4 the second of these has size less than N times the prime reciprocal series, which is less than 1 / 2 by assumption, we find that the complementary part M must be at least N / 2 large. (Contributed by Mario Carneiro, 6-Aug-2014)
Ref | Expression | ||
---|---|---|---|
Hypotheses | prmrec.1 | |
|
prmrec.2 | |
||
prmrec.3 | |
||
prmrec.4 | |
||
prmrec.5 | |
||
prmrec.6 | |
||
prmrec.7 | |
||
Assertion | prmreclem5 | |