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DFA Alphabet Transition Completeness

Audit every declared state/alphabet pair for absent transition keys in a finite deterministic automaton; no sink completion or unbounded alphabet.

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Description

List missing state/alphabet transition pairs in a declared deterministic automaton.

A deterministic transition maps a state and one literal alphabet symbol to at most one next state. A partial table may leave some pairs undefined; a complete table defines every state/symbol pair. Tracing one word, exploring all graph paths and changing the accepting set are distinct operations. IDs and symbols use exact string identity.

List missing state/alphabet transition pairs in a declared deterministic automaton.

When to use this tool

Use completeness evidence before any operation that depends on a transition for every state/symbol pair.

How to use the tool and how it works

  1. Enter transitionsJson, states, alphabet using the definitions below. Serialize JSON text fields in the decoded shape shown below.
  2. Run the operation. Resolve input-format errors before interpreting an output.
  3. Read result.missing, using the stated boundary, ordering, sign and absence conventions.

Validate state and alphabet membership and unique transition keys. For every state/alphabet pair, report it if no transition is defined, preserving state-then-alphabet bank order.1

Input fieldMeaning and unitsAccepted input
transitionsJsonJSON array of {from,symbol,to} literal string records, preserving transition indexes. Determinism is checked or audited as described above.Text, at most 8,192 UTF-16 code units; narrower grammar/range rules also apply.
statesDistinct literal declared state IDs in bank order; full automaton operations require at least one.Dense list of at most 128 literal strings, each at most 8,192 UTF-16 units.
alphabetDistinct literal alphabet symbols in bank order; an empty alphabet is allowed.Dense list of at most 128 literal strings, each at most 8,192 UTF-16 units.

These decoded structures show the examples inside JSON text fields. Supply their serialized JSON strings as input.

json
{
  "transitionsJson": [
    {
      "from": "a",
      "symbol": "x",
      "to": "b"
    },
    {
      "from": "b",
      "symbol": "x",
      "to": "b"
    }
  ]
}
Output fieldInterpretation
resultObject containing the fields below.
result.missingMissing endpoint or state/symbol evidence with the original indexes or bank ordering described above.
json
{
  "input": {
    "transitionsJson": "[{\"from\": \"a\", \"symbol\": \"x\", \"to\": \"b\"}, {\"from\": \"b\", \"symbol\": \"x\", \"to\": \"b\"}]",
    "states": [
      "a",
      "b",
      "c"
    ],
    "alphabet": [
      "x"
    ]
  },
  "output": {
    "result": {
      "missing": [
        {
          "state": "c",
          "symbol": "x"
        }
      ]
    }
  }
}

Limitations and assumptions

  • No missing transition or sink state is inserted. Empty alphabets have no required pairs; endpoint coverage and determinism errors are rejected before the completeness report.
  • Transition JSON is an array of {from,symbol,to} string records. Tools requiring a declared automaton use a nonempty distinct state bank and distinct alphabet, validate endpoints and symbols, and reject duplicate [from,symbol] keys. Trace-only tools validate keys without inferring a declared universe. No normalization or implicit sink is provided.
  • Every declared outer field is required and unknown outer fields are rejected. Strings and JSON text have size limits, lists are bounded to 128 entries, and JSON nesting/node counts are bounded. Tighter operation-specific bounds stated above take precedence.
  • Numeric outputs must remain finite and within safe-integer magnitude. Original record indexes and cell coordinates are zero-based; stated half-open ranges exclude their end.

Alternative or Complementary methods

Use endpoint and duplicate-key audits before transformations. Check completeness before complementing an accepting set, and preserve the declared alphabet, start-state convention and acceptance policy with exported tables.

References

  1. Tool behavior and example: DFA Alphabet Transition Completeness — tool.io

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