# Revision history [back]

The extension method is really designed for towers of finite fields.

To define a finite field as an extension of the prime field, one can use the GF or FiniteField constructor.

It can take an optional modulus argument:

sage: K.<a> = GF(2^1000, modulus=x^1000 + x^5 + x^4 + x^3 + 1)


sage: GF?


or

sage: FiniteField?


The extension method is really designed for towers of finite fields.

To define a finite field as an extension of the prime field, one can use the GF or FiniteField constructor.

It can take an optional modulus argument:

sage: K.<a> = GF(2^1000, modulus=x^1000 + x^5 + x^4 + x^3 + 1)


sage: GF?

sage: FiniteField?

Fixing the bug in the extension method reported in the question is tracked at: