Normal Subgroups and Quotient Groups: Examples and Counterexamples
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.
✓ 5 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 5 not AI-judged were verified by owner audit (typically over a confirmed judge false positive), not failures.
1 · Prerequisites
Abstract Algebra
Number Theory
Real Analysis
2 · Logical flowchart
3 · Items
Counterexample
A nonnormal two-element subgroup of Sym({1,2,3}) makes coset multiplication depend on representatives
Example
The three-cycle subgroup of Sym({1,2,3}) is normal and its quotient has two elements
Example
The four cosets of 4ℤ in (ℤ,+) reproduce addition modulo 4
Example
G/{e} reproduces G, while G/G is the one-element quotient group
Example