Classification of nontrivial valuations on the rational numbers (source code)

= Classification of nontrivial valuations on the rational numbers
{title2=$v=c\,v_p$}

An additive nontrivial <valuation> on the rational field is equivalent to exactly one <P-adic valuation>. Integers have nonnegative values; some prime must have positive value, and <Bézout's identity> prevents two distinct primes from doing so. Unique factorization then gives the formula, with $c>0$ in the real-valued case. The trivial <valuation> is a separate possibility if admitted by the definition.