I have a question concerning Bertrand's postulate in "Proofs from the BOOK", on page 8:
$\prod_{p \leq {2m+1}} p=\left(\prod_{p \leq m+1} p \right)\left( \prod_{{m+1} Why did the author split the product up in the way he did it and not in another way? Are there any reasons? Any help would be appreciated.