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Question 23266: Epsilon Closure Reaches States without Consuming Input

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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R0045-23266 · q-20261014-advance-20261111-r07-nondeterministic-finite-automaton-0041

Original question and givens

Use the complete finite epsilon-NFA: states=[s15, m15, f15, d15], alphabet=[a15, b15], start=s15, final_states=[f15], transitions=[[s15, null, m15], [s15, null, d15], [m15, a15, m15], [m15, b15, f15]]. Transitions are [from,input symbol or null,to]; null is epsilon and consumes no input. States are nonempty because the start belongs to them, but alphabet/final sets and the transition relation may be empty. The relation may be multivalued, not deterministic or total. A configuration is [state,input position]; acceptance requires one finite path consuming the entire input and ending final. Seed states=[s15]. Give (seed_states, epsilon_closure, closure_certificate, certificate).

  • G001 — Use the complete finite epsilon-NFA: states=[s15, m15, f15, d15], alphabet=[a15, b15], start=s15, final_states=[f15], transitions=[[s15, null, m15], [s15, null, d15], [m15, a15, m15], [m15, b15, f15]]. Transitions are [from,input symbol or null,to]; null is epsilon and consumes no input. States are nonempty because the start belongs to them, but alphabet/final sets and the transition relation may be empty. The relation may be multivalued, not deterministic or total. A configuration is [state,input position]; acceptance requires one finite path consuming the entire input and ending final. Seed states=[s15]. Give (seed_states, epsilon_closure, closure_certificate, certificate).

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

source operation=nfa-epsilon-closure;original snapshot and mathematics retained

After

explicit ordered source output fields=[seed_states, epsilon_closure, closure_certificate, certificate]

Conditions: none

Retain the historical interface marker while listing source fields without JavaScript.Tags and No retain their claim scope;source-protocol ordering is not a mathematical proof.

Step identifiers and dependencies

Rule: source_ordered_interface_explicit_without_javascript · Uses: G001

S002 · implies

Before

ORIGINAL transition index=0;[from,input_or_null,to]=[s15, null, m15];state carrier=[s15, m15, f15, d15];alphabet=[a15, b15]

After

state endpoints legal;symbol either declared input or null EPS consuming0;ORIGINAL row position retained,including duplicate rows

Conditions: none

This is a relation,not a total single-valued function.Retain duplicate,multivalued and missing edges;null consumes0 and is not an alphabet string.

Step identifiers and dependencies

Rule: nfa_EVERY_original_relation_row_roles_empty_multi_EPS_legal · Uses: G001, S001

S003 · implies

Before

ORIGINAL transition index=1;[from,input_or_null,to]=[s15, null, d15];state carrier=[s15, m15, f15, d15];alphabet=[a15, b15]

After

state endpoints legal;symbol either declared input or null EPS consuming0;ORIGINAL row position retained,including duplicate rows

Conditions: none

This is a relation,not a total single-valued function.Retain duplicate,multivalued and missing edges;null consumes0 and is not an alphabet string.

Step identifiers and dependencies

Rule: nfa_EVERY_original_relation_row_roles_empty_multi_EPS_legal · Uses: G001, S002

S004 · implies

Before

ORIGINAL transition index=2;[from,input_or_null,to]=[m15, a15, m15];state carrier=[s15, m15, f15, d15];alphabet=[a15, b15]

After

state endpoints legal;symbol either declared input or null EPS consuming0;ORIGINAL row position retained,including duplicate rows

Conditions: none

This is a relation,not a total single-valued function.Retain duplicate,multivalued and missing edges;null consumes0 and is not an alphabet string.

Step identifiers and dependencies

Rule: nfa_EVERY_original_relation_row_roles_empty_multi_EPS_legal · Uses: G001, S003

S005 · implies

Before

ORIGINAL transition index=3;[from,input_or_null,to]=[m15, b15, f15];state carrier=[s15, m15, f15, d15];alphabet=[a15, b15]

After

state endpoints legal;symbol either declared input or null EPS consuming0;ORIGINAL row position retained,including duplicate rows

Conditions: none

This is a relation,not a total single-valued function.Retain duplicate,multivalued and missing edges;null consumes0 and is not an alphabet string.

Step identifiers and dependencies

Rule: nfa_EVERY_original_relation_row_roles_empty_multi_EPS_legal · Uses: G001, S004

S006 · implies

Before

ORIGINAL states=[s15, m15, f15, d15],alphabet=[a15, b15],start=s15,final_states=[f15];complete relation=[[s15, null, m15], [s15, null, d15], [m15, a15, m15], [m15, b15, f15]]

After

states nonempty with actual start;alphabet/final set/relation MAY be EMPTY;definition qualification does NOT prove determinism,totality,DFA equivalence or a successful run

Conditions: none

An empty final set is legal and recognizes the empty language;an empty alphabet is legal too.A qualified definition supplies no accepting path,determinism or DFA-equivalence proof.

Step identifiers and dependencies

Rule: nfa_qualified_definition_EMPTY_alphabet_finals_edges_allowed · Uses: G001, S005

S007 · implies

Before

NFA ORIGINAL EPS closure:ORIGINAL seed list=[s15];complete state carrier=[s15, m15, f15, d15]

After

initialize unique closure=[s15];seeds themselves are reachable by zero EPS steps;RAW seed list not changed

Conditions: none

Seeds may be empty or repeated.Retain the raw seed list while the closure set deduplicates and includes zero-step reachability.An EPS cycle alone gives no acceptance.

Step identifiers and dependencies

Rule: nfa_EPS_closure_contains_ORIGINAL_seeds_duplicates_preserved · Uses: G001, S006

S008 · implies

Before

NFA ORIGINAL EPS closure:stage=0;ORIGINAL-relation EPS pass from previous set=[s15]

After

ALL [ORIGINAL index,from,to,from_in_previous] EPS rows=[[0, s15, m15, Yes], [1, s15, d15, Yes]];next unique set=[d15, m15, s15];stable=No

Conditions: none

Each added state has an EPS predecessor in the preceding set and hence a finite seed path.Any EPS-closed superset of the seeds contains every stage.Finiteness gives stabilization at the complete least closure,without consuming input.

Step identifiers and dependencies

Rule: nfa_EVERY_EPS_saturation_stage_least_reachable_set · Uses: G001, S007

S009 · implies

Before

NFA ORIGINAL EPS closure:stage=1;ORIGINAL-relation EPS pass from previous set=[d15, m15, s15]

After

ALL [ORIGINAL index,from,to,from_in_previous] EPS rows=[[0, s15, m15, Yes], [1, s15, d15, Yes]];next unique set=[d15, m15, s15];stable=Yes

Conditions: none

Each added state has an EPS predecessor in the preceding set and hence a finite seed path.Any EPS-closed superset of the seeds contains every stage.Finiteness gives stabilization at the complete least closure,without consuming input.

Step identifiers and dependencies

Rule: nfa_EVERY_EPS_saturation_stage_least_reachable_set · Uses: G001, S008

Reverse checks

  • 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

([s15], [d15, m15, s15], Yes, finite_epsilon_reachability_without_input_consumption)

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: 6a63015d7960b170073dbdf16c9fd9dcb987df3d70870e28fe15affc58df5ef6
  • candidate record SHA-256: 478e81a14f6c29d37bd59ea2fc14c398ff5c244edf43414667bfd2e565e0c6b0
  • semantic review receipt SHA-256: 357d7ad7a6726b2a757558d3b9586a408ade06526cc023da093719c292704438
  • question-first witness SHA-256: 99cefe17e98c7a74321801cf72df6d02fc95b6a6b78aa335accb7e11ed467b2a
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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