Locate the Actual Zero Left Port in Native Routes
Abstract
Locate the Actual Zero Left Port in Native Routes.
Theorem 1.1 (The Even Route Has Its Zero Left Port at the Exact Index).
Lean statement: D5/S3/Combinatorics/Graph/PrefixReversal/NativeBoundaryRoutePositions.native_even_left_zero_piece_position
Proof. Machine-checked in Lean as D5/S3/Combinatorics/Graph/PrefixReversal/NativeBoundaryRoutePositions.native_even_left_zero_piece_position (✓ std3). ∎
Source. Repository-derived.
Commentary.
For actual ordered special-child pieces whose finishes follow the even native route at order 2s+2, native port injectivity identifies the unique piece finishing at the zero left port. Its index is exactly s+1, so it comes after the first rooted boundary piece.
Theorem 1.2 (The Odd Route Includes the Empty Ladder Case).
Lean statement: D5/S3/Combinatorics/Graph/PrefixReversal/NativeBoundaryRoutePositions.native_odd_left_zero_piece_position
Proof. Machine-checked in Lean as D5/S3/Combinatorics/Graph/PrefixReversal/NativeBoundaryRoutePositions.native_odd_left_zero_piece_position (✓ std3). ∎
Source. Repository-derived.
Commentary.
For actual ordered special-child pieces whose finishes follow the odd native route at order 2s+3, the zero left port occurs precisely at index s+1. This exact statement includes order three and supplies the later-cut position used by literal Q slicing.
References
- Truth anchor:
D5/S3/Combinatorics/Graph/PrefixReversal/NativeBoundaryRoutePositions.native_even_left_zero_piece_position - Truth anchor:
D5/S3/Combinatorics/Graph/PrefixReversal/NativeBoundaryRoutePositions.native_odd_left_zero_piece_position - Dependency: D5/S3/Combinatorics/Graph/PrefixReversal/NativeSpecialBoundaryInstances