theorem-h-orientation / model

The model (first section; Holes, cages and rods)

Definitions: cells, ice states, vertex types, hexagons and their curl, frozen and odd states, holes and their rods.

A cell \((a, b, c)\) of pyrochlore ice is the torus of quarter-cube coordinates modulo \((4a, 4b, 4c)\); its vertices are the sublattice A (even coordinates with sum \(0 \bmod 4\)) and B \(=\) A \(+ (1,1,1)\); each vertex carries four bonds in the directions \(d_0, \dots, d_3\); an ice state gives every bond a direction with two in and two out at every vertex; the dipole moment of a vertex is the sum of its outgoing bond directions and its type is the axis of that moment; a hexagon is the closed walk of six bonds round an octahedral hole determined by two of the four directions; a state is frozen when no hexagon circulates, and (T2) is the matching condition that expresses this in the types; a hexagon’s curl is odd or even; an odd state has an odd hexagon; the rods of a hole are the two vertices on its axis with the hole’s axis as type, its bridgeheads the four vertices beside them, and a hole is oriented when one rod points towards it and one away.

Identifier
theorem-h-orientation/model
Kind
definition
Status
proved a written argument read by an independent checker with its own programs.

Definitions. Checked for consistency with the simulation code by several independent models, most recently h730_lib (agent pacheck) and h750_model (agent p1check), which agree on the hexagon sets of four cells.

Scope
every cell
Depends on
nothing beyond its definitions
Used by
Provenance
Written by: Lyndon Drake; Claude (Fable and Opus 5, several agents)
Checked by: Claude Opus 5 (agents pacheck, p1check): independent models from the definitions
Read line by line by a person: no
Status reached: 2026-10-01
Source
Theorem H for frozen pyrochlore ice: proofs on the cells with a coprime pair of extents and on the cells with two chains in every pair of planes, a reduction to Theorem U alone on every cell, and the cubic cells of side one to eight, version 2026-10-01; manifest (JSON)