%0 Journal Article %T The sum of irreducible fractions with consecutive denominators is never an integer in a very weak arithmetic %A Victor Pambuccian %J Mathematics %D 2008 %I arXiv %X Two theorems of elmentary arithmetic, one stating that the sum of the reciprocals of any number of consecutive positive integers is never an integer, and a generalization thereof by Trygve Nagell, are shown to be provable inside a very weak arithmetic, Richard Kaye's $PA^-$, in which there is no induction axiom whatsoever. %U http://arxiv.org/abs/0801.3639v1