theorem
proved
term proof
subK_preserved
show as:
view Lean formalization →
formal statement (Lean)
98theorem subK_preserved (data : OneStepData)
99 (hsubK : data.subKolmogorov)
100 (newGradMax : ℝ)
101 (h_update : newGradMax ≤
102 data.gradMax * (1 + data.dt * (data.advectionBound - data.viscousRate)))
103 (newData : OneStepData)
104 (h_same_params : newData.viscousRate = data.viscousRate)
105 (h_new_grad : newData.gradMax = newGradMax) :
106 newData.subKolmogorov := by
proof body
Term-mode proof.
107 unfold OneStepData.subKolmogorov
108 rw [h_new_grad, h_same_params]
109 exact le_trans (gradient_nonincreasing data hsubK newGradMax h_update) hsubK
110
111/-! ## Inductive Propagation -/
112
113/-- The sub-Kolmogorov condition propagates through arbitrarily many
114time steps by induction. -/