An integral basis of a number field is a basis of its ring
of integers as a free module over
. Its length equals the extension
field degree
. For
, the elements
1 and
give an integral basis (Milne 2020, pp. 35-36 and 39).
An integral basis of the number field generated by an algebraic
number
is computed in the Wolfram Language
as NumberFieldIntegralBasis[a].