logic-consistency-check

Logic Consistency Check

Requirements drift. Specs accumulate. A document written over weeks by multiple people — or a set of decisions made incrementally — can contain contradictions that nobody noticed because each piece was reviewed in isolation.

This skill reads the whole and finds where the parts disagree.

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Your Process

Step 1: Map the claims Before checking for consistency, inventory what the document asserts:

• Goals and objectives stated
• Constraints and non-negotiables stated
• Assumptions stated or implied
• Decisions and their stated rationale
• Any numbered requirements or acceptance criteria

This map is what gets checked for internal coherence — not whether any claim is true, but whether the claims are consistent with each other.

Step 2: Check goal-constraint conflicts Do the stated goals require violating stated constraints? Common patterns:

• A performance goal that requires more resources than the budget allows
• A simplicity goal combined with a feature list that requires complexity
• A timeline that requires skipping steps the quality requirements depend on

Step 3: Check requirement-requirement conflicts Do individual requirements contradict each other?

• Two requirements that can't both be satisfied simultaneously
• A requirement that is a special case of another requirement but handled differently
• Requirements that use the same term with different implicit meanings (equivocation across requirements)

Step 4: Find edge cases that expose conflicts Some contradictions only appear at the boundary. Ask: what happens when...

• Input is at its minimum and maximum values simultaneously required
• Two features interact that were designed independently
• The happy path assumption fails
• A stated exception meets a stated rule

Step 5: Check assumption coherence Implicit assumptions are the most dangerous source of inconsistency — stated nowhere, but load-bearing everywhere. Surface them:

• What must be true for each requirement to be satisfiable?
• Do any of those assumptions contradict each other?
• Do any assumptions contradict stated facts?

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Human Check-in

Before proceeding, use the AskUserQuestion tool:

• Question: "How do you want to run this?"
• Header: "Scope"
• Options:
  • Full analysis — Complete all steps, reasoning shown throughout
  • Key findings only — Bottom-line output, skip step-by-step detail
  • Contradictions list only — Flag the specific inconsistencies without full analysis
  • Refine the framing — Adjust what we're analyzing before starting

Proceed based on their selection.

Output Format

Subject: [what was checked]

Contradictions Found

Type	Item A	Item B	Conflict
Goal vs constraint	[goal]	[constraint]	[why they conflict]
Requirement vs requirement	[req]	[req]	[why they conflict]
Assumption vs fact	[assumption]	[fact]	[why they conflict]

"None found" if clean.

Edge Cases That Expose Conflicts

• [scenario]: [which requirements or goals it breaks]

Hidden Assumptions

• [assumption]: [which requirements depend on it; whether it's safe]

Verdict [Overall consistency assessment — clean, minor issues, or significant conflicts that need resolution before proceeding]

Recommended Resolutions

• [Specific change per conflict — which item to amend and how]

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Notes

Not every inconsistency is equally urgent. Flag severity: a contradiction in core requirements is a blocker; an ambiguity in an edge case may just need a decision logged. The goal is to make implicit conflicts explicit so they can be resolved consciously rather than discovered in production.

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What's Next

After delivering this output, use AskUserQuestion to offer the next move:

• Question: "Consistency checked. What's next?"
• Header: "Next"
• Options:
  • /logic-fixer — Resolve the inconsistencies found
  • /aesthetic-coherence-check — Check conceptual and aesthetic coherence alongside logical consistency
  • /identity-values-clarification — Resolve any values conflicts underlying the inconsistencies
  • Done — Wrap up and synthesise what we have so far