Alphabeta Math

Modules, Submodules, Quotient Modules and the Isomorphism Theorems

About this page
How statement and proof provenance work

The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.

  • Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
  • AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
  • AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.

These labels describe origin, not correctness: citations and verification chips remain separate evidence.

✓ 7 results · all verified · 0 also independently AI-judged
Every result on this page is machine-checked by a proof checker and read in full and owner-audited; the judge is an additional, independent cross-model AI review of the proofs. The 7 not AI-judged were verified by owner audit (typically over a confirmed judge false positive), not failures.
1 · Prerequisites
2 · Logical flowchart

3 · Items

Definition

Unital left and right modules over a ring; unqualified module means left module

Lemma

In a module, 0_Rm=0_M, r0_M=0_M, (-r)m=-(rm) and r(-m)=-(rm)

Definition

Submodule of a module

Lemma

The one-step submodule criterion; intersections and sums of submodules are submodules

Definition

Generated submodule, cyclic and finitely generated modules, module basis and free module

Definition

Simple module: a nonzero module with no proper nonzero submodule

Definition

Annihilators, torsion elements and the torsion subset of a module

Definition

Quotient module M/N with scalar multiplication on additive cosets

Definition

Module homomorphism and isomorphism, kernel, image and cokernel

Theorem

Kernels and images of module homomorphisms are submodules, and injectivity is equivalent to trivial kernel

Theorem

The quotient action is well defined and makes M/N a module

Proposition

The canonical map M→ M/N is a surjective module homomorphism with kernel N; thus every submodule is a kernel

Theorem

A module homomorphism vanishing on N factors uniquely through M/N

Theorem

First isomorphism theorem for modules: M/ker f congimf

Sources