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TauCeti.LinearAlgebra.FreeModule.ModN

Coordinates in the basis of G / nG #

For a ℤ-basis b of a free ℤ-module G and n ≠ 0, Mathlib's ModN.basis b is the basis of ModN G n = G / nG over ℤ / n formed by the classes of the vectors of b. This file records that the coordinates of the class of v in this basis are the coordinates of v in b, reduced modulo n.

Main statements #

@[simp]
theorem ModN.basis_repr_mkQ {G : Type u_1} {ι : Type u_2} [AddCommGroup G] {n : ℕ} [NeZero n] (b : Module.Basis ι ℤ G) (v : G) (i : ι) :
((basis b).repr ((mkQ n) v)) i = ↑((b.repr v) i)

The coordinates of the class of v in ModN.basis b are the coordinates of v in b, reduced modulo n.

@[simp]
theorem ModN.basis_repr_mk {G : Type u_1} {ι : Type u_2} [AddCommGroup G] {n : ℕ} [NeZero n] (b : Module.Basis ι ℤ G) (v : G) (i : ι) :
((basis b).repr (Submodule.Quotient.mk v)) i = ↑((b.repr v) i)

The coordinates of the class of v in ModN.basis b are the coordinates of v in b, reduced modulo n: the form of ModN.basis_repr_mkQ for Submodule.Quotient.mk.