sudoku

Constraint topology

Record the cell layout, alphabet and membership of each row, column and region without inferring missing geometry from appearance alone.

1. Which cells exist, which symbols are permitted, and which rows, columns and regions contain each cell? definition
2. Does the supplied layout establish a standard 9×9 grid with nine 3×3 regions, or does it require a different explicit topology? boundary

Declared rule contract

Record the applicable all-different requirements and any additional or replacement constraints, including the interpretation of visual markings.

1. Which groups must contain each permitted symbol exactly once, and which variant constraints also apply? definition
2. What supplied instructions establish the meaning of diagonals, cages, paths or other markings, including any rules about unmarked cells? provenance

Fixed given map

Identify the value and position of every given, together with any uncertainty in transcription or extraction.

1. Which cell values were supplied as fixed givens rather than entered during solving? definition
2. What original puzzle representation supports the given map, and which symbols or positions remain uncertain? provenance

Entries and candidate meaning

Distinguish committed entries, branch assumptions and candidate notes; record whether notes are complete and how candidates were derived.

1. Which cells are empty, committed or tentative, and which candidate sets are complete rather than partial notes? measurement
2. Which entries or candidate removals may be reversed without changing the original givens or rules? action

Conflicts and dead ends

Identify repeated symbols, violated variant constraints and proved impossibility, retaining the entries and reasoning responsible for each diagnosis.

1. Which current entries directly violate a row, column, region or declared variant constraint? measurement
2. Has a dead end been proved, such as a soundly derived empty candidate set or a required symbol with no possible position, and on which assumptions does that proof depend? measurement

Solution evidence

Record whether a full grid satisfies all rules and givens, and whether the original puzzle has zero, exactly one or multiple solutions.

1. Does the proposed completion fill every playable cell, preserve all givens and satisfy every declared constraint? measurement
2. What evidence establishes the original puzzle's solution multiplicity, and does it exclude solver-added entries from the premise? provenance

Deduction support and hint depth

Connect each proposed move to its supporting cells, candidates and constraints, identifying any dependence on uniqueness or a branch assumption.

1. Which placement or elimination follows, and what cells, constraints and assumptions justify it? action
2. Should the next hint identify a unit to inspect, name a technique, explain the deduction or reveal the placement? action

Branch or revise

Record whether the next operation explores an assumption within the current puzzle or creates a revised puzzle requiring fresh validation.

1. Does the operation assume a candidate for search, or change a given, region or rule and therefore revise the puzzle? boundary
2. After the operation, what must be restored or rechecked, including branch-dependent deductions, solvability, uniqueness and any difficulty rating? action

Kinds and varieties

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

1. Which of these kinds and varieties hold for the sense of sudoku this model covers, and on what evidence? provenance

Identifiers and schemes

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

1. Which of these identifiers and schemes hold for the sense of sudoku this model covers, and on what evidence? provenance

Standards and regulation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

1. Which of these standards and regulation hold for the sense of sudoku this model covers, and on what evidence? provenance

Real-world use

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

1. Which of these real-world use hold for the sense of sudoku this model covers, and on what evidence? provenance

Typical measurements

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

1. Which of these typical measurements hold for the sense of sudoku this model covers, and on what evidence? provenance

Failure modes and hazards

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

1. Which of these failure modes and hazards hold for the sense of sudoku this model covers, and on what evidence? provenance

Regional variation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

1. Which of these regional variation hold for the sense of sudoku this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of sudoku this model covers, and on what evidence? provenance