Reference · The Applied Higher-Order Functions catalogue
rainbow.algorithms.proofs.ahof.dfp
AHoF O28 DFP (Davidon-Fletcher-Powell): a quasi-Newton method whose curvature update uses the step vector s = x_{k+1} - x_k: step-vector x-new x-old = x-new - x-old. Worked: 3-1=2. Values proved by signed cross-product equivalence. Proved native and axiom-free. Requires signed/subtract, signed/from-nnrat, signed/equivalent (all in the D63 checkpoint). Scope (measured by the kernel): this module has 2 worked instances (statements about specific values) and 1 definitional unfoldings (true by unfolding a definition). None of its theorems is a guarantee about the algorithm for all inputs; `lein verify rainbow.algorithms.proofs.ahof.dfp` prints this classification.
dfp/step-vector
dfp/step-vector : (x₁ x₂ : ℚ) → ℚ
ℚ = signed/SignedRational
dfp/step-example
dfp/step-example : → ℚ
ℚ = signed/SignedRational
dfp/no-step
dfp/no-step : → ℚ
ℚ = signed/SignedRational
dfp/step-vector-unfold
dfp/step-vector-unfold : (a b : ℚ) → dfp/step-vector a b = a - b
- = signed/subtract= = equality/Eqℚ = signed/SignedRational
dfp/step-example-is-2
dfp/step-example-is-2 : → dfp/step-example = signed/from-nnrat 2
= = signed/equivalent: equality of rational values
dfp/no-step-is-0
dfp/no-step-is-0 : → dfp/no-step = signed/from-nnrat 0
= = signed/equivalent: equality of rational values