What problem does it solve? Research notes often contain scattered formulas with unclear assumptions, mixed identities and approximations, and no coherent derivation line. This Skill turns messy theory notes into a structured derivation built around one invariant object, ready for internal alignment or paper writing. ## Core Features & Use Cases - Invariant-Object Framing: Identifies the single quantity that survives across regimes, then derives proxies, decompositions, and interpretations from it. - Step Classification: Labels every derivation step as identity, proposition, approximation, or interpretation so claims are never overstated. - Structured Outputs: Produces a mainline derivation note, a paper-style theory draft, or a blocker report when notes cannot support a coherent derivation. - Use Case: A researcher has notes on a network cost model with a simplified and a general regime. The Skill unifies both under one global quantity, derives the marginal decomposition, and separates the formal derivation from remarks and scope statements. ## Quick Start Use the formula-derivation skill to turn my theory notes into a paper-ready derivation with explicit assumptions and regime boundaries.