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TauCeti.Algebra.CharZero.IntCast

Roots of nonzero integers in a ring of characteristic zero #

In a ring of characteristic zero the integers embed injectively, so the image of a nonzero integer is nonzero. Consequently an n-th root (n ≠ 0) of a nonzero integer is itself nonzero; for example, a square root of a nonzero integer in a number field.

Main results #

theorem TauCeti.ne_zero_of_pow_eq_intCast {K : Type u_1} [Ring K] [CharZero K] {x : K} {n : ℕ} {c : ℤ} (hn : n ≠ 0) (hx : x ^ n = (algebraMap ℤ K) c) (hc : c ≠ 0) :
x ≠ 0

In characteristic zero, an n-th root of a nonzero integer, for n ≠ 0, is nonzero.