C506 — Integral endpoints require pivot compatibility
Question
What extra condition distinguishes an integral width ladder from integral dates?
Inputs
{
"map": "D_E,a(x)=(25x−2a)/23",
"integer_source_and_pivot": true
}
Sources
[
"Strategy §5C",
"C505; exact algebra"
]
Opened utc
2026-09-27T22:45:39.171525+00:00
Results
{
"one_stage_iff": "x congruent a mod23",
"two_stage_condition": "first outputs integral; second pivot congruent to every first output mod23",
"pair_condition": "if original width belongs to529Z, integral first outputs share one residue mod23",
"same_pivot_two_stage_iff": "x−a divisible by529",
"proof": "25x−2a ≡2(x−a) mod23 and2 is invertible mod23; for a repeated pivot D_E,a²(x)=a+(625/529)(x−a), gcd(625,529)=1"
}
Finding
Widths lose the pivot term; endpoints retain it. A529-multiple width guarantees a shared second-stage residue after an integral first stage, but it does not supply a licensed pivot of that residue.
Reassessment
Apply this criterion to the already supplied C480 pivots and the fixed12026 trial, without choosing new pivots.
Checks
{
"coprime": true,
"common_residue_width": true
}
Closed utc
2026-09-27T22:45:39.171772+00:00
Record provenance
Exact record hash: 260e6718bf7692c169bc4c7e10531a4f8684d9ad927a762ce3e5610c50872518
Source journal: Research_Cycles/C0482_C0531/journal.json