# Flip Assumptions

> Test claims by forming contrapositive

- Skill: `synapseradio/flip-assumptions-2` (Agent Skill)
- Install (CLI): `npx skillmds@latest add synapseradio/flip-assumptions-2`
- Raw SKILL.md: https://api.skillmd.com/api/skills/synapseradio/flip-assumptions-2/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: synapseradio (https://skillmd.com/u/synapseradio)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/synapseradio/flip-assumptions-2

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Follow these steps:

### 1. Identify the claim

Target: the claim in the current context.

### 2. Identify the conditional structure

Locate the underlying "if P then Q". It often hides in causal language ("X causes Y"), categorical statements ("all X are Y"), or implied relationships ("X means Y"). Make the conditional explicit.

### 3. Form the contrapositive

Negate both parts and reverse them: "if not-Q then not-P". This is logically equivalent to the original.

### 4. Compare verification difficulty

Which form is easier to test against evidence? The original may require proving something exists; the contrapositive, that something is absent. One direction often reveals clearer evidence paths.

### 5. Surface hidden assumptions

Notice what the contrapositive makes explicit that the original obscured: unstated prerequisites, whether the claim is weaker than it appeared.

### 6. Test both directions

Examine evidence for both forms. If the contrapositive is obviously false, the original is too — often a faster path to flawed reasoning.