IndisputableMonolith.Aesthetics.SymmetryGroupPreference
The module enumerates the seventeen wallpaper groups in IUC notation and supplies supporting functions for orbit counts and symmetry ratios. Researchers in pattern aesthetics or crystallographic symmetry would cite the standardized list when quantifying preference via J-cost. The module is purely definitional and imports only the time quantum from Constants together with cost primitives.
claimThe set of seventeen wallpaper groups in IUC notation, ordered as in Schattschneider 1978, together with the functions orbitCount : WallpaperGroup → ℕ and symmetryRatio : WallpaperGroup → ℝ that measure orbit structure and symmetry density.
background
The module sits in the Aesthetics domain and imports the RS time quantum τ₀ = 1 tick from Constants and the cost machinery from Cost. WallpaperGroup is defined as an inductive enumeration of the seventeen plane symmetry groups; orbitCount returns the number of distinct orbits under the group action on the plane, while symmetryRatio normalizes this count to a value in (0,1]. These definitions prepare symmetry data for later J-cost comparisons.
proof idea
This is a definition module, no proofs.
why it matters in Recognition Science
The module supplies the canonical list of wallpaper groups required for any downstream symmetry-preference metric. It directly supports the definitions of symmetryRatio and wallpaperJ that appear among its siblings, providing the enumeration step needed before J-cost or phi-ladder comparisons can be applied to aesthetic patterns.
scope and limits
- Does not enumerate three-dimensional space groups.
- Does not prove any algebraic relations among the groups.
- Does not compute explicit J-cost values for patterns.
- Does not address non-crystallographic or aperiodic symmetries.
depends on (2)
declarations in this module (25)
-
inductive
WallpaperGroup -
def
orbitCount -
def
maxOrbitCount -
theorem
orbitCount_p6m -
theorem
orbitCount_pos -
theorem
orbitCount_le_max -
def
symmetryRatio -
theorem
symmetryRatio_pos -
theorem
symmetryRatio_p6m -
theorem
symmetryRatio_le_one -
def
wallpaperJ -
theorem
wallpaperJ_nonneg -
theorem
wallpaperJ_p6m_eq_zero -
theorem
wallpaperJ_pos_of_ne_one -
theorem
wallpaperJ_p1_pos -
theorem
wallpaperJ_p6m_le -
theorem
Jcost_anti_mono_on_unit_interval -
theorem
wallpaperJ_mono_in_orbits -
def
preference -
theorem
preference_p6m_eq_zero -
theorem
preference_p6m_max -
theorem
preference_anti_mono_in_orbits -
structure
SymmetryGroupPreferenceCert -
def
symmetryGroupPreferenceCert -
theorem
symmetry_group_preference_one_statement