Erdős Problem #137: the combined four-range splice #
A single "control panel" unifying the three deterministic non-powerfulness routes proved elsewhere
in the repository, parametric in three range predicates Mid Sq High : ℕ → ℕ → Prop. Given a
CoversAll4 decomposition of every (k, n) (with k ≥ 3, 1 ≤ n) into
- the small range
n ≤ k— discharged unconditionally by Bertrand (upper_half_prime_not_powerful); - the middle/prime range
Mid— a primep > kis a block term (prime_range_not_powerful, fed byPrimeInBlockOnRange Mid); - the squarefree-count range
Sq— the squarefree count beats the deterministic capacity (squarefree_range_not_powerful, fed bySqfreeCapacityBeatenOnRange Sq); - the high range
High— any externally supplied non-powerfulness input, whose predicate carries its own side conditions (e.g.High k n := 6 ≤ k ∧ k^3 < nto plug in the crudeg = 6thresholdnot_powerful_of_large_g6, or5 ≤ k ∧ k^{5/3+η} < nfor the smoothg = 5bound), so the ambient3 ≤ kguard need not match the route's own,
it concludes ¬ Powerful (F k n) for every such (k, n). The analytic inputs (Baker–Harman–Pintz
on Mid, Pandey-type squarefree counts on Sq, the abc block bound behind High) live ENTIRELY
inside the three premises: Lean never assumes any of them, so nothing here pretends to formalize
BHP, Pandey, Mertens, or abc. This is the four-range analogue of
abstract_splice_no_counterexamples, with the new squarefree-count range slotted between the prime
range and the high range.
Four-range coverage. Every (k, n) with k ≥ 3, 1 ≤ n is small (n ≤ k), middle
(Mid), squarefree-rich (Sq), or high (High). On the intended instantiation Mid is the
Baker–Harman–Pintz prime-gap range, Sq is the Pandey squarefree-count range, and High is a
crude or smooth radical threshold; coverage is the (external) statement that these four ranges
exhaust n > 0.
Equations
Instances For
The combined four-range splice. Parametric in Mid Sq High. Given a CoversAll4
decomposition, a ranged prime input on Mid, a squarefree-capacity input on Sq, and a
non-powerfulness input on High, the product F k n is not powerful for every k ≥ 3, 1 ≤ n.
Each case is discharged by the corresponding deterministic theorem; the analytic content stays in
the premises.