FenchelNielsenZomorrodian.Profinite.CompactFuchsianSignature
This module develops Fenchel--Nielsen--Zomorrodian presentation reductions, period relations, reindexings, and quotient maps.
def compactFuchsianSignature
(σ : FenchelSignature) (hCompact : σ.IsCompact)
(hPeriods : 3 ≤ σ.numPeriods) : FuchsianSignature where
orbitGenus := σ.orbitGenus
numCusps := σ.numCusps
numPeriods := σ.numPeriods
periods := σ.periods
period_ge_two := σ.period_ge_two
numCusps_eq_zero := hCompact
numPeriods_ge_three := hPeriodsPromote a compact Fenchel signature with at least three periods to the compact Fuchsian signature used by the discrete compact three-step theorem.