lorenzLimitDays
plain-language theorem explainer
The declaration defines the Lorenz predictability limit as 15 days via direct division of the established gap value 45 by 3. Climate forecasters and RS modelers cite it to bound operational horizons where skill remains above random on the phi-ladder. The definition is a one-line arithmetic reduction from the upstream gap computation.
Claim. The Lorenz predictability limit is defined as $15$ days, obtained by dividing the gap of $45$ by $3$.
background
Gap is the product of closure and Fibonacci factors and equals 45. The anchor residue display function is $F(Z) = (1 + Z/φ) / ln(φ)$. In this module forecast skill decays on the phi-ladder with adjacent horizon ratios $1/φ$, yielding five canonical timescales whose total count equals the spatial dimension $D=5$. The local setting equates the empirical Lorenz limit of roughly two weeks to gap-45/3.
proof idea
One-line definition that evaluates gap-45/3 directly to the constant 15.
why it matters
This supplies the numerical Lorenz bound required by the ClimateForecastCert structure, which also enforces five timescales, strictly positive skill, and the $1/φ$ decay ratio. It closes the operational climate step that links the gap-45 result from the forcing chain to forecast horizons. The placement touches the phi-ladder and eight-tick octave landmarks.
Switch to Lean above to see the machine-checked source, dependencies, and usage graph.