MathGloss

An integral domain RR is a unique factorization domain if

  1. Every nonzero, non-unit rRr\in R can be written as a product of irreducibles; and
  2. Whenever p1pn=q1qmp_1\cdots p_n=q_1\cdots q_m for pi,qjp_i,q_j irreducible and m,nNm,n\in\mathbb N, then m=nm=n and there is a relabeling/reordering of the qjq_j such that qiq_i is associate to pip_i for all 1in1\leq i\leq n.

In particular, for every association class of irreducibles, we can choose a representative, and let PP be the collection of such representatives so that every rRr\in R can be written uniquely as r=upPpepr= u\prod_{p\in P} p^{e_p} for uu a unit and all but finitely many of the epe_p equal to zero.

Wikidata ID: Q1052579