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Question 13613: Partition the Full Vertex Carrier into Reachability Classes

On this page
  1. Original question and givens
  2. Definition and scope
  3. Step-by-step derivation
  4. Reverse checks
  5. Result
  6. This question review and source binding

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R0026-13613 · q-20261014-advance-20261028-r07-connected-component-0038

Original question and givens

Use the complete finite undirected loop-free simple graph on Fin(7)={0,…,6} with edge set=[[0, 1], [0, 2], [0, 6], [1, 5], [2, 4], [3, 4], [3, 5]]. Loops and duplicate undirected edges are forbidden. Connectivity is complete path reachability, not just one traversal fragment. Length-zero paths make every vertex reachable from itself, including isolated vertices. Do not switch to directed weak/strong, infinite or dynamic connectivity. Give (components,count). List each class increasingly and order classes by their least unseen vertex.

  • G001 — Use the complete finite undirected loop-free simple graph on Fin(7)={0,…,6} with edge set=[[0, 1], [0, 2], [0, 6], [1, 5], [2, 4], [3, 4], [3, 5]]. Loops and duplicate undirected edges are forbidden. Connectivity is complete path reachability, not just one traversal fragment. Length-zero paths make every vertex reachable from itself, including isolated vertices. Do not switch to directed weak/strong, infinite or dynamic connectivity. Give (components,count). List each class increasingly and order classes by their least unseen vertex.

Definition and scope

Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate.

Step-by-step derivation

S001 · implies

Before

full carrier Fin(7);raw undirected edges=[[0, 1], [0, 2], [0, 6], [1, 5], [2, 4], [3, 4], [3, 5]]

After

canonical simple edges=[[0, 1], [0, 2], [0, 6], [1, 5], [2, 4], [3, 4], [3, 5]];full adjacency rows=[[1, 2, 6], [0, 5], [0, 4], [4, 5], [2, 3], [1, 3], [0]]

Conditions: none

Build adjacency on the full carrier,rejecting loops and duplicate undirected edges.Vertices absent from edges retain empty rows;do not switch to directed connectivity.

Step identifiers and dependencies

Rule: component_full_undirected_graph_includes_isolates · Uses: G001

S002 · implies

Before

class representative0:start vertex=0;complete adjacency=[[1, 2, 6], [0, 5], [0, 4], [4, 5], [2, 3], [1, 3], [0]]

After

initial visited=[0];path to start=[0];edge length0

Conditions: none

The start reaches itself by a length-zero path.Even an isolated vertex must be included rather than omitted for having no edges.

Step identifiers and dependencies

Rule: component_zero_length_reflexive_path · Uses: G001, S001

S003 · implies

Before

class representative0:layer=0;frontier=[0];all frontier neighbors=[1, 2, 6]

After

previously seen=[0];new vertices=[1, 2, 6]

Conditions: none

At each layer inspect every neighbor of every frontier vertex,then add only unvisited distinct labels.Do not stop at a plausible-looking fragment.

Step identifiers and dependencies

Rule: component_complete_frontier_expansion · Uses: G001, S002

S004 · implies

Before

class representative0:new vertex=1;earliest frontier parent=0;parent path=[0]

After

append actual parent edge;reachable path=[0, 1]

Conditions: none

Extend the established parent path by an original graph edge,so every added vertex really is reachable.

Step identifiers and dependencies

Rule: component_each_new_vertex_path_witness · Uses: G001, S003

S005 · implies

Before

class representative0:new vertex=2;earliest frontier parent=0;parent path=[0]

After

append actual parent edge;reachable path=[0, 2]

Conditions: none

Extend the established parent path by an original graph edge,so every added vertex really is reachable.

Step identifiers and dependencies

Rule: component_each_new_vertex_path_witness · Uses: G001, S004

S006 · implies

Before

class representative0:new vertex=6;earliest frontier parent=0;parent path=[0]

After

append actual parent edge;reachable path=[0, 6]

Conditions: none

Extend the established parent path by an original graph edge,so every added vertex really is reachable.

Step identifiers and dependencies

Rule: component_each_new_vertex_path_witness · Uses: G001, S005

S007 · implies

Before

class representative0:layer=1;frontier=[1, 2, 6];all frontier neighbors=[0, 4, 5]

After

previously seen=[0, 1, 2, 6];new vertices=[4, 5]

Conditions: none

At each layer inspect every neighbor of every frontier vertex,then add only unvisited distinct labels.Do not stop at a plausible-looking fragment.

Step identifiers and dependencies

Rule: component_complete_frontier_expansion · Uses: G001, S006

S008 · implies

Before

class representative0:new vertex=4;earliest frontier parent=2;parent path=[0, 2]

After

append actual parent edge;reachable path=[0, 2, 4]

Conditions: none

Extend the established parent path by an original graph edge,so every added vertex really is reachable.

Step identifiers and dependencies

Rule: component_each_new_vertex_path_witness · Uses: G001, S007

S009 · implies

Before

class representative0:new vertex=5;earliest frontier parent=1;parent path=[0, 1]

After

append actual parent edge;reachable path=[0, 1, 5]

Conditions: none

Extend the established parent path by an original graph edge,so every added vertex really is reachable.

Step identifiers and dependencies

Rule: component_each_new_vertex_path_witness · Uses: G001, S008

S010 · implies

Before

class representative0:layer=2;frontier=[4, 5];all frontier neighbors=[1, 2, 3]

After

previously seen=[0, 1, 2, 4, 5, 6];new vertices=[3]

Conditions: none

At each layer inspect every neighbor of every frontier vertex,then add only unvisited distinct labels.Do not stop at a plausible-looking fragment.

Step identifiers and dependencies

Rule: component_complete_frontier_expansion · Uses: G001, S009

S011 · implies

Before

class representative0:new vertex=3;earliest frontier parent=4;parent path=[0, 2, 4]

After

append actual parent edge;reachable path=[0, 2, 4, 3]

Conditions: none

Extend the established parent path by an original graph edge,so every added vertex really is reachable.

Step identifiers and dependencies

Rule: component_each_new_vertex_path_witness · Uses: G001, S010

S012 · implies

Before

class representative0:layer=3;frontier=[3];all frontier neighbors=[4, 5]

After

previously seen=[0, 1, 2, 3, 4, 5, 6];new vertices=[]

Conditions: none

At each layer inspect every neighbor of every frontier vertex,then add only unvisited distinct labels.Do not stop at a plausible-looking fragment.

Step identifiers and dependencies

Rule: component_complete_frontier_expansion · Uses: G001, S011

S013 · implies

Before

class representative0:final visited=[0, 1, 2, 3, 4, 5, 6];all [vertex,neighbors,outside neighbors] rows=[[0, [1, 2, 6], []], [1, [0, 5], []], [2, [0, 4], []], [3, [4, 5], []], [4, [2, 3], []], [5, [1, 3], []], [6, [0], []]]

After

no edge leaves visited;every visited vertex has a path;visited equals full reachable set

Conditions: none

Path witnesses give visited⊆reachable.At completion no edge leaves visited.If a path reached outside,it would have a first leaving edge,a contradiction,so reachable⊆visited.Both directions establish the whole component,not a traversal order.

Step identifiers and dependencies

Rule: component_reachable_and_closed_set_completeness · Uses: G001, S012

S014 · implies

Before

least unvisited representative=0;derived component=[0, 1, 2, 3, 4, 5, 6]

After

all visited labels=[0, 1, 2, 3, 4, 5, 6]

Conditions: none

Sort labels within each class and order classes by the least unvisited representative.BFS discovery order is not the canonical component order.

Step identifiers and dependencies

Rule: component_least_unvisited_class_order · Uses: G001, S013

Reverse checks

  • S014 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S013 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S012 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S011 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S010 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S009 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S008 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S007 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S006 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S005 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S004 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S003 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S002 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S001 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.

Result

([[0, 1, 2, 3, 4, 5, 6]], 1)

The full substitutions and premise checks give the original answer; source identity,format and status are unchanged.

This question review and source binding

Review date: 2026-10-26

Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof.

Source hashes and review receipts
  • input commit: 0f7be61e2c22317a4075561dc822c87d881a50db
  • original question SHA-256: a1346fa943d845430895e830076f60d89267c93aaf3637729f5535088d4b279b
  • candidate record SHA-256: 326c1dc99493b6d560428d32bb9f1b9ec890b6c75ed42ce4ae938070b5ba0371
  • semantic review receipt SHA-256: f335caca08574c9f949c141083c66655fee51c227d45d80a3ddb7d78f862d798
  • question-first witness SHA-256: cc7ba54738af91a6871fc1c20e45ad8f2b434392273fa334bd16a3b2238f4a77
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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