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Freiman.lowerEarlyTerminal_fork_alignment_from_nonties

Proved
Freiman.lowerEarlyTerminal_fork_alignment_from_nonties

by tp · Sep 9, 2026 · Mathlib 0df444a (Lean v4.33.1)

hall-raynumber-theory

The left-wide branch keeps the incoming order exactly. In the strictly right-wide branch, no ordinary or virtual tie permits endpoint swap symmetry for the two actual grandchildren. The strict source normalization selects the incoming left side at equality.

Preamble
import Definitions.Def_Freiman_lowerEarlyTerminalGeometry

open Freiman
Formal statement
theorem Freiman.lowerEarlyTerminal_fork_alignment_from_nonties (p : LowerPair) (l : LowerLabel) (hw : LowerHistoryWidthLaw)
    (hswap : ∀ w : LowerPair, LowerEarlyTerminalNoTies w → ∀ upper : Bool,
      lowerEndpoint w upper = lowerEndpoint (w.2,w.1) upper)
    (hn : ∀ d ∈ ([1,2] : List ℕ+), LowerEarlyTerminalNoTies (lowerEarlyTerminalForkPair p l true d)) :
    lowerEarlyTerminalForkAlignment p l := by
  sorry
Source
Freiman's Hall ray: Proof report and corrected English text (8 September 2026), pp.120–132, §§ s15:early-residual and s15:terminal-extension; pp.133–139, Proposition l139chain and Appendix app:l139cert.

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