The factor command now accepts an additional argument, an algebraic extension specifying an algebraic number field over which the polynomial is to be factored. The extension can be specified as a single RootOf or radical, or in the case of multiple extensions, a list or set of such. Example: factor the polynomial over

> factor(y^4-2,sqrt(2)); 2 1/2 2 1/2 (y + 2 ) (y - 2 )

> alias(alpha = RootOf(x^2-2)); > factor(y^4-2,alpha); 2 2 (y + alpha) (y - alpha)

An algebraic extension can also be given to the roots and irreduc functions.

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