Reference · The Applied Higher-Order Functions catalogue
rainbow.algorithms.proofs.ahof.lqr
LQR linear feedback control (Kochenderfer Decision Making D7.11), one of the signed-subtraction cluster deferred in August until the signed layer landed. The control law is the linear feedback u = -K x: negate the gain-scaled state. `control/lqr-action gain state = signed/negate (signed/scale gain state)`, a higher-order composition of the two signed primitives, and the worked theorem proves the concrete action for gain 2, state 3 is equivalent to -6 by signed cross-product reflexivity -- the standard worked-instance idiom of the 222 catalog. Native and axiom-free on D63; a proved native module at module level, not a formally credited ledger row (that pipeline is a separate follow-up per the catalog workflow).
control/lqr-action
control/lqr-action : (x₁ : ℚ≥0) (x₂ : ℚ) → ℚ
ℚ = signed/SignedRationalℚ≥0 = nnrat/NonnegativeRational
control/lqr-action-worked
control/lqr-action-worked : → control/lqr-action 2 (signed/from-nnrat 3) = signed/negate (signed/from-nnrat 6)
= = signed/equivalent: equality of rational values
control/lqr-action-sign-reversing
control/lqr-action-sign-reversing : (gain : ℚ≥0) (state : ℚ) (state-nonnegative : signed/nonnegative state) → control/lqr-action gain state ≤ 0
0 = signed/zeroℚ = signed/SignedRationalℚ≥0 = nnrat/NonnegativeRational≤ = signed/at-most