lemma
proved
Jcost_exp_nonneg
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IndisputableMonolith.Cost.Derivative on GitHub at line 118.
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115 simp
116
117/-- J(e^L) ≥ 0 for all L (AM-GM). -/
118lemma Jcost_exp_nonneg (L : ℝ) : 0 ≤ Jcost (exp L) :=
119 Jcost_nonneg (exp_pos L)
120
121-- TODO: For small L, J(e^L) ≈ L²/2 (quadratic)
122-- lemma Jcost_exp_approx (L : ℝ) (hL : |L| ≤ 1) :
123-- |Jcost (exp L) - L ^ 2 / 2| ≤ |L| ^ 3 / 2
124
125/-! ## Connection to Ethics/Harm -/
126
127/-- Matches the linBondDelta definition in Harm.lean. -/
128theorem linJ_matches_harm_def (x L : ℝ) :
129 linJ x L = ((x - x⁻¹) / 2) * L := rfl
130
131/-- **Main Theorem**: The harm linear term is the correct directional derivative.
132
133 This justifies using linBondDelta in the harm decomposition. -/
134theorem harm_linearization_correct (x L : ℝ) (hx : 0 < x) :
135 -- The linearization linJ captures the first-order behavior of J along exp paths
136 linJ x L = deriv Jcost x * x * L :=
137 linJ_eq_derivative_times_x x L hx
138
139end Cost
140end IndisputableMonolith