Cost
Cost supplies the typed carrier for real-valued cost observables inside the RS-native measurement system. Acoustics and action-principle authors cite it when they instantiate J-cost functions or hearing-loss penalties. The declaration is a one-line abbreviation that delegates all algebraic structure (zero, addition, coercion to ℝ) to the Quantity structure.
claimLet $Cost$ denote the type of real-valued quantities equipped with the semantic label $CostUnit$.
background
The RS-Native Measurement Framework represents every observable as a real number tagged with a unit type. Quantity U is the structure that packages a real val together with the unit U and supplies the zero, addition, subtraction, and coercion-to-ℝ instances. CostUnit is an empty inductive type whose sole purpose is to serve as the semantic tag for cost quantities.
proof idea
This is a direct abbreviation that instantiates Quantity at the CostUnit inductive type. No lemmas or tactics are invoked; the declaration simply re-exports the real carrier and its algebraic instances.
why it matters in Recognition Science
Cost is the carrier used by forty downstream declarations, among them srCost, hearingLossPenalty_nonneg, and costRateEL_const_one. It anchors the J-cost function (derived from the Recognition Composition Law and T5 J-uniqueness) inside the typed measurement system, guaranteeing that nonnegativity and reciprocal symmetry are inherited automatically. The definition therefore closes the interface between the abstract forcing chain and concrete observables such as speech-recognition costs.
scope and limits
- Does not assign numerical values to any cost.
- Does not enforce positivity or other constraints on the underlying real.
- Does not link CostUnit to external SI units.
- Does not populate CostUnit with concrete constructors.
formal statement (Lean)
204abbrev Cost := Quantity CostUnit
used by (40)
-
hearingLossPenalty_nonneg -
hearingLossPenalty_zero -
srCost -
srCost_nonneg -
srCost_pos_off_threshold -
srCost_reciprocal_symm -
srCost_zero_at_threshold -
costRateEL_const_one -
costRateELHolds -
costRateEL_iff_const_one -
costRateEL_implies_const_one -
Jcost_quadratic_leading_coeff -
Jcost_taylor_quadratic -
pleasure -
pleasure_max_at_one -
pleasure_symmetric -
aestheticCost -
aestheticCost_nonneg -
aestheticCost_pos_off_optimum -
aestheticCost_reciprocal_symm -
aestheticCost_zero_at_optimum -
Jcost_anti_mono_on_unit_interval -
preference_anti_mono_in_orbits -
symmetryRatio_le_one -
wallpaperJ -
wallpaperJ_nonneg -
wallpaperJ_p6m_eq_zero -
wallpaperJ_pos_of_ne_one -
cost_algebra_unique -
cost_algebra_unique_aczel