Finite segment overlays on the source side #
The outer source curve is deliberately not polygonal, but every nonouter source edge of a generated pair is polygonal. This module extracts an exact finite straight-segment cover of that compact nonboundary carrier and overlays it with the local window grid. It is the finite geometric core of the forward half of the quantitative-refinement recursion.
Blueprint #
Schoenflies.SourceNonboundarySegmentCover— an exact finite segment presentation of the current source nonboundary skeleton.Schoenflies.GeneratedPair.exists_sourceNonboundarySegmentCover— every generated pair has such a presentation.Schoenflies.SourceNonboundarySegmentCover.localOverlay— the old compact source core overlaid with one fine local grid.Schoenflies.SourceNonboundarySegmentCover.LocalOverlayRelabeling.graph— the finite inner overlay, freshly relabelled and adjoined to the old wild outer graph.Schoenflies.SourceNonboundarySegmentCover.LocalOverlayRelabeling.isSourceExtension— all local source-extension fields, leaving only the two global attachment properties explicit.Schoenflies.SourceNonboundarySegmentCover.LocalOverlayRelabeling. isSourceExtension_of_source_connected_two_common— the global properties follow from the carried source-connectedness invariant and two distinct common source/grid vertices.
Replacing a drawing by a pointwise equal parametrization on the graph's own edges preserves all drawing axioms.
Compatible plane drawings whose carriers meet only at common vertices form a plane drawing on their union.
A nonempty walk in a plane drawing has connected geometric carrier.
A finite exact straight-segment presentation of the compact nonboundary source skeleton.
The straight segments covering the nonboundary carrier.
No listed segment is degenerate.
The listed segments occupy exactly the compact nonboundary source graph.
- source (Q : Piece) : Q ∈ self.pieces → ∃ e ∈ P.str.skel.edgeSet, e ∉ P.str.outerGraph.edgeSet ∧ Q.seg ⊆ Graph.edgeArc P.src.drawing e
Every listed segment came from one old nonouter source edge.
Instances For
Every generated pair has a finite exact segment presentation of its compact polygonal nonboundary source skeleton.
The two finite segment families in the source local-grid overlay.
Equations
- Q.localPieces p s epsilon = Q.pieces ++ Schoenflies.localGridEdges p s (Schoenflies.localGridCount s epsilon)
Instances For
The compact old source core overlaid with a fine local grid. Old nonboundary vertices and any prescribed attachment points are retained as overlay vertices.
Equations
- Q.localOverlay p s epsilon extra = Schoenflies.attachGraph (Q.localPieces p s epsilon) (extra ++ P.sourceNonboundaryGraph.vertexFinset.toList)
Instances For
Every source segment of the local overlay is nondegenerate.
The source local overlay is a finite straight-line plane graph.
The local overlay occupies exactly the old compact source core together with the grid.
The whole old compact source core is retained by the local overlay.
The whole fine local grid is retained by the source overlay.
Every vertex of the raw local grid is retained as a vertex of the combined straight-line overlay.
Away from overlay vertices, an overlay edge meeting a raw local-grid edge is one of its subdivision pieces.
The straight-line local overlay contains a plane subdivision of the raw local grid.
Every edge of the source local overlay is a subsegment either of the old nonboundary source cover or of the local grid.
Every vertex of the compact old source core is explicitly retained as a vertex of the local overlay.
Every old nonouter edge belongs to the compact source-core graph.
Away from overlay vertices, an inner-overlay edge meeting an old open nonboundary edge is one of that edge's subdivision pieces.
Containment in the source domain #
The complete local grid carrier lies in its closed square window.
If the closed local window lies in the source domain, then so does the complete finite inner overlay of the old nonboundary source skeleton with that grid.
Every edge of the finite inner overlay is polygonal and its nonvertex points lie in the open source domain. For an old nonouter edge, weak admissibility puts its open 1-cell in the interior; if the old arc touches the wild boundary, the touching point is an old core vertex and hence an overlay vertex. Grid-sourced edges lie in the chosen interior window.
The compact nonboundary source carrier meets the wild outer curve only at vertices common to the nonboundary and outer source graphs.
Relabelling and adjoining the wild outer graph #
Fresh abstract edge names for the finite straight-line inner overlay.
- name : Piece → γ
Fresh cell names for the local-grid overlay.
- name_inj : Set.InjOn self.name (Q.localOverlay p s epsilon extra).edgeSet
Instances For
An infinite cell-name type supplies a relabelling of the inner overlay disjoint from every name already used by the current generated structure.
The old outer graph realized on the wild source curve.
Equations
- _w.outerGraph = Graph.map P.src.pos P.str.outerGraph
Instances For
The finite inner overlay after allocation of fresh abstract edge names.
Equations
- w.innerGraph = (Q.localOverlay p s epsilon extra).relabelEdges w.name ⋯
Instances For
The mixed source extension graph.
Equations
- w.graph = w.outerGraph.union w.innerGraph
Instances For
The mixed drawing uses the original parametrizations on the wild outer edges and straight segments on every freshly named inner edge.
Equations
- w.drawing e = if e ∈ P.str.outerGraph.edgeSet then P.src.drawing e else (Q.localOverlay p s epsilon extra).relabelDrawing w.name Schoenflies.segmentDrawing e
Instances For
The two edge families are disjoint and therefore compatible.
On an old outer edge the mixed drawing is the old source drawing.
On an inner edge the mixed drawing is the relabelled straight-line drawing.
The mixed drawing restricts to a plane drawing on the old wild outer graph.
The mixed drawing restricts to a plane drawing on the straight-line inner overlay.
The old outer part of the mixed graph occupies exactly the wild source curve.
The inner part occupies exactly the finite straight-line local overlay.
The mixed outer/inner source graph is a plane drawing whenever the local window lies in the open source domain.
The mixed source graph is finite.
The mixed source graph occupies the wild outer curve, the old compact nonboundary carrier, and the complete local grid.
The complete old source skeleton is retained by the mixed graph.
Every old source vertex is explicitly retained as a mixed-graph vertex.
The mixed source graph stays in the closed source domain.
Every mixed edge is either an old outer edge on the wild curve or a polygonal inner edge whose nonvertex points lie in the open source domain.
An edge of the mixed graph meeting an old open source edge away from mixed vertices is one of that edge's subdivision pieces.
The mixed graph contains a plane subdivision of the complete old source drawing.
The trace of the old source skeleton in the mixed graph remains 2-connected.
Every raw local-grid vertex is retained in the mixed graph.
The entire raw local-grid carrier is retained in the mixed graph.
An edge of the mixed graph meeting a raw local-grid edge away from mixed vertices is a subdivision piece of that grid edge. An old outer edge cannot meet the grid at all because the grid window is strictly inside the source domain.
The mixed graph also contains a plane subdivision of the raw local grid.
The local-grid trace inside the mixed graph remains 2-connected.
Two distinct mixed vertices lying on both the old source skeleton and the local grid make the whole mixed graph 2-connected. The two plane-subdivision traces are 2-connected and together contain every mixed vertex.
If the old open source skeleton is connected and meets the local grid, then the mixed carrier remains connected after the wild outer curve is removed.
The mixed graph is a complete source extension once its two global attachment properties are supplied. All finiteness, drawing, subdivision, containment, and edge-geometry fields are automatic from the exact source cover and the interior-window hypothesis.
With two common source/grid vertices, only connectedness off the wild outer curve remains to obtain the complete source extension.
At an admissible stage, two distinct common source/grid vertices give the complete source extension. One common point joins the two connected carriers off the boundary; both common vertices make their 2-connected subdivision traces glue.