Not able to be reduced or lessened.
Impossible to divide further into representations of lower dimension by means of any similarity transformation.
Unable to be factorized into polynomials of lower degree, as (x² + 1).
Not able to be brought to a simpler or reduced form.
Unable to be factored into smaller integers; prime.
Whose numerator and denominator share no common factor greater than 1.
that its only divisors are units and associates.
Not containing a sphere of codimension 1 that is not the boundary of a ball.
Such a polynomial
That cannot be subdued; indomitable.