Square-free element
In mathematics, a square-free element is an element r of a unique [factorization domain] R that is not divisible by a non-trivial square. This means that every s such that is a unit of R.
Alternate characterizations
Square-free elements may be also characterized using their prime decomposition. The unique factorization property means that a non-zero non-unit r can be represented as a product of prime elementsThen r is square-free if and only if the primes pi are pairwise non-associated.