Alphabeta Math
ExampleConstruction: Literature-sourcedVerification: AI-adaptedprecheck passaudited 2026-08-11
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.

⟨a,b∣a2, b2, aba−1b−1⟩≅(Z/2)×(Z/2)

Example

The Klein four-group has the presentation

⟨a,b∣a2, b2, aba−1b−1⟩≅(Z/2)×(Z/2),

where a and b correspond to (1,0) and (0,1).

Facts & Assumptions

Given: The presentation P=⟨a,b∣a2,b2,aba−1b−1⟩ and the direct-product group (Z/2)×(Z/2).

[L1]

A map of generators that sends every relator to the identity extends uniquely to a homomorphism from the presented group (Von Dyck's theorem: maps of generators that satisfy the relators extend uniquely from a presented group).

Verification

technique · constructive
1.1

Sending a to (1,0) and b to (0,1) kills the two square relators and the commutator in the abelian direct product, so [L1] constructs a homomorphism π:P→(Z/2)×(Z/2).

L1construct
1.2

The commutator relation gives ab=ba, and the square relations reduce both exponents modulo 2, so every element of P has one of the forms e,a,b,ab.

given
2.1

Their images are (0,0),(1,0),(0,1),(1,1), which are distinct and exhaustive by [L2]; together with step 1.2, this makes π bijective.

L2step 1.1step 1.2
3.1

Hence P is isomorphic to (Z/2)×(Z/2), the Klein four-group.

step 2.1discharge-construct∎

Depends on

Used by

Nothing in the library uses this result yet.

Dependency tree · two levels

32 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.

Sources