OAI/NumberTheory/Ostmann/Construction/BackwardTargets.lean

GitHub source file

9 declarations, 0 contain sorry, 0 declared as axioms

The backwards pivot-target recurrence

For coefficients c_j = 2^j J + a_j - Delta_j, the pivot target is c_j plus the sum of all later pivot targets. This constructs the recurrence, rather than assuming that its simultaneous equations have a solution.

  1. def OAI.Ostmann.backwardTargets line 17
  2. theorem OAI.Ostmann.backwardTargets_length line 21
  3. theorem OAI.Ostmann.backwardTargets_sum_cons line 26
  4. theorem OAI.Ostmann.backwardTargets_drop line 31
  5. theorem OAI.Ostmann.backwardTargets_get line 40
  6. theorem OAI.Ostmann.backwardTargets_nonneg line 52
  7. theorem OAI.Ostmann.backwardTargets_sum_upper line 65
  8. theorem OAI.Ostmann.backwardTargets_lower_last line 78

    Source documentation

    Every target is at least the final coefficient when the coefficients are nonnegative. Thus the last pivot controls the common lower scale.

    theorem backwardTargets_lower_last (cs : List ℝ) (hne : cs ≠ [])
        (hcs : ∀ c ∈ cs, 0 ≤ c) :
        ∀ t ∈ backwardTargets cs, cs.getLast hne ≤ t := by
    …

    Mentions: OAI.Ostmann.backwardTargets

  9. theorem OAI.Ostmann.backwardTargets_each_upper line 102