mathlib3

ea3dac31 - fix(number_theory/cyclotomic/basic): change variable names, fix doc (#16901)

fix(number_theory/cyclotomic/basic): change variable names, fix doc (#16901) The docstring of `is_cyclotomic` was using `a ∈ S` and `n` (`∈ S`) interchangeably. I've switched to `n` uniformly, because I think `a` risks being confused as a term of the ring `A`.