About foundamental fundamental theorem of algebra, there is a large collection different demonstrations.
I ask: there is there some proof that avoid avoids AC (choise axiom) choice axiom)?
In a general topos (with natural number object) there are the two construction constructions of real numbers (generalization generalizations of the classical Dedekind and Cauchy classicalconstructions) that are different.
In ZF theory, are the Dedekind and Cauchy constructions different? (in In the "Cauchy" reals, operates on a real number $r$ through a choosechoice of a Cauchy sequence converging to $r$).r$.)
