# Sequential Thinking

> Use when a problem's answer depends on a chain of prior conclusions and jumping straight to one risks skipping a step — before answering, when it's unclear where to start, or when an earlier reasoning error needs to surface at the step that caused it.

- Skill: `presidenteog/sequential-thinking` (Agent Skill)
- Install (CLI): `npx skillmds@latest add presidenteog/sequential-thinking`
- Raw SKILL.md: https://api.skillmd.com/api/skills/presidenteog/sequential-thinking/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: PresidenteOG (https://skillmd.com/u/presidenteog)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/presidenteog/sequential-thinking

---


# sequential-thinking

Sequential thinking is a structured reasoning protocol for problems where jumping to an answer skips the sub-questions that determine whether the answer is right. It works by making the chain of reasoning explicit and checkable — so errors surface at the step level, not buried in a conclusion.

## Qué hace esta skill

- Decomposes any complex problem into the sub-questions that must be answered first
- Maps the dependency order between sub-questions (which must be resolved before which)
- Resolves each sub-question explicitly: question stated → evidence reviewed → conclusion drawn
- Synthesizes sub-conclusions into a final answer, clearly separated from the reasoning chain
- Runs a sanity check: "Does this conclusion hold if assumption X is wrong?"

## Cuándo usarla

- Debugging a logic error where the symptoms don't point obviously to the cause
- Making a system design or architecture decision with multiple interdependent constraints
- Strategy or pricing decisions where the right answer depends on several prior judgments
- Any problem where your first instinct might be anchoring on the wrong frame
- When someone gives you a recommendation and you want to stress-test it

## Proceso

1. **State the problem clearly:** One sentence — what decision needs to be made or what question answered?

2. **Problem decomposition:**
   > "To answer this, I first need to know: [A], [B], [C]"
   List every sub-question. Don't skip ones that feel obvious — they contain hidden assumptions.

3. **Dependency map:**
   Which sub-questions depend on others being answered first?
   ```
   A → B → D
        ↘ C → D
   ```
   Resolve in dependency order, not in the order you thought of them.

4. **Resolve each sub-question explicitly:**
   ```
   Sub-question: <state it exactly>
   Evidence: <what we know, what we can observe, what's uncertain>
   Conclusion: <single declarative statement>
   Confidence: High / Medium / Low
   ```

5. **Synthesis:**
   Combine sub-conclusions into the final answer. State it in one paragraph first, then elaborate.

6. **Sanity check:**
   Pick the 2 most load-bearing assumptions. Ask: "If [assumption] is wrong, does the conclusion reverse?"
   - If yes → flag as a risk, get evidence on that assumption
   - If no → conclusion is robust, proceed

### Anti-patterns this skill catches
- Jumping to solution before the problem is understood
- Treating a symptom as a root cause (the error is at a different layer)
- Making multiple assumptions at once without tracking them
- Anchoring to the first idea and reasoning backward to justify it
- Confusing "I don't know" with "probably fine"

### Output structure
```
PROBLEM: <one sentence>

SUB-QUESTIONS:
1. [A] — depends on: nothing
2. [B] — depends on: [A]
3. [C] — depends on: [A], [B]

RESOLUTION:
[A]: <evidence> → <conclusion> (Confidence: High)
[B]: <evidence> → <conclusion> (Confidence: Medium)
[C]: <evidence> → <conclusion> (Confidence: High)

FINAL ANSWER:
<synthesis paragraph>

SANITY CHECK:
If [assumption X] is wrong → [impact on conclusion]
If [assumption Y] is wrong → [impact on conclusion]
```

## Ejemplo de prompt

> Estoy pensando en cobrar $99/mes en lugar de $49/mes. No sé si aumentar el precio va a matarme las conversiones o si en realidad me ayuda. Ayúdame a razonar esto paso a paso antes de decidir.

## Relación con otras skills

| Situación | Skill |
|---|---|
| El problema es de validación de mercado, no de razonamiento interno | `mom-test` |
| El problema es un audit de diseño — ya tienes información, necesitas criterio | `ui-ux-pro-max` |
| Necesitas entender la motivación del cliente antes de razonar la estrategia | `jobs-to-be-done` |