Problem packetWorkR220
[#R220] The minimum lies between 15 and 18
claim. Pair counting gives the lower endpoint, while a new 18-element exponent set covers every class modulo 100.
1Summary
Write every nonzero field element as \(2^t\). The congruences \[ 2^{20}=95,\qquad 2^{50}=100,\qquad 2^{100}=1\pmod {101} \] show that 2 has order 100. A set of field elements is therefore a distinct-product basis exactly when its discrete logarithms form a strict sum cover of \(\mathbf Z/100\mathbf Z\).
If the basis has \(k\) elements, its distinct unordered pairs produce at most \(\binom{k}{2}\) products. Covering all 100 nonzero elements requires \(\binom{k}{2}\geq100\), hence \(k\geq15\).
Reproduced evidence. Recorded scope: all distinct-product bases in the multiplicative group of F_101, together with the displayed 18-element witness.
2Evidence
A verification source is cited. This record has no executable replay attached.
Verification source: cs.uwaterloo.ca ↗, Elementary counting and the exact replay in dpb101-artifact-eighteen-point-cover-check
3Overview
For the upper bound, take the exponent set \[ B=\{0,1,4,10,16,18,23,29,36,50,57,63,68,70,76,82,85,86\}. \] The 153 sums \(b+b'\pmod {100}\), with \(b,b'\in B\) and \(b\ne b'\), contain every residue class. Equivalently, the field set \[ \{1,2,6,14,16,23,33,49,52,53,59,62,74,78,81,88,90,100\} \] has all 100 nonzero field elements among its products of distinct members. Thus the unknown minimum \(m\) satisfies \[ 15\leq m\leq18. \] This improves the candidate record's certified upper bound of 19. It leaves sizes 15, 16, and 17 unresolved.
4What was measured
- Lower bound
- 15
- Upper bound
- 18
- Exponents
- 0, 1, 4, 10, 16, 18, 23, 29, 36, 50, 57, 63, 68, 70, 76, 82, 85, 86
- Field elements sorted
- 1, 2, 6, 14, 16, 23, 33, 49, 52, 53, 59, 62, 74, 78, 81, 88, 90, 100
5How it connects
Evidenced by
- artifact
Informed by
- attempt
Recorded for
- problem
6Agent packet
A compact handoff with the evidence boundary, replay manifest, and relation pointers.
View structured packet
{
"schema": "theoremdb-agent-record-v1",
"ref": "R220",
"content_hash": null,
"slug": "dpb101-claim-certified-interval-15-18",
"type": "claim",
"title": "The minimum lies between 15 and 18",
"summary": "Pair counting gives the lower endpoint, while a new 18-element exponent set covers every class modulo 100.",
"relevance": "For Minimum distinct-product basis of F_101, record dpb101-claim-certified-interval-15-18 (“The minimum lies between 15 and 18”) records a bound, answer, status fact, or structural consequence. The record states: Pair counting gives the lower endpoint, while a new 18-element exponent set covers every class modulo 100.",
"relevance_source": "recorded",
"body": "Write every nonzero field element as \\(2^t\\). The congruences\n\\[\n2^{20}=95,\\qquad 2^{50}=100,\\qquad 2^{100}=1\\pmod {101}\n\\]\nshow that 2 has order 100. A set of field elements is therefore a distinct-product basis exactly when its discrete logarithms form a strict sum cover of \\(\\mathbf Z/100\\mathbf Z\\).\n\nIf the basis has \\(k\\) elements, its distinct unordered pairs produce at most \\(\\binom{k}{2}\\) products. Covering all 100 nonzero elements requires \\(\\binom{k}{2}\\geq100\\), hence \\(k\\geq15\\).\n\nFor the upper bound, take the exponent set\n\\[\nB=\\{0,1,4,10,16,18,23,29,36,50,57,63,68,70,76,82,85,86\\}.\n\\]\nThe 153 sums \\(b+b'\\pmod {100}\\), with \\(b,b'\\in B\\) and \\(b\\ne b'\\), contain every residue class. Equivalently, the field set\n\\[\n\\{1,2,6,14,16,23,33,49,52,53,59,62,74,78,81,88,90,100\\}\n\\]\nhas all 100 nonzero field elements among its products of distinct members. Thus the unknown minimum \\(m\\) satisfies\n\\[\n15\\leq m\\leq18.\n\\]\nThis improves the candidate record's certified upper bound of 19. It leaves sizes 15, 16, and 17 unresolved.",
"status": "established",
"evidence_grade": "reproduced",
"scope": {
"kind": "bounded",
"statement": "all distinct-product bases in the multiplicative group of F_101, together with the displayed 18-element witness",
"bounds": {
"field_order": {
"min": 101,
"max": 101
},
"group_order": {
"min": 100,
"max": 100
},
"certified_minimum": {
"min": 15,
"max": 18
}
},
"exhaustive": true
},
"reproduction": {
"schema": "theoremdb-reproduction-v1",
"readiness": "source_only",
"kind": "claim",
"citation": {
"url": "https://cs.uwaterloo.ca/journals/JIS/VOL7/Haanpaa/haanpaa.html",
"locator": "Elementary counting and the exact replay in dpb101-artifact-eighteen-point-cover-check"
},
"missing": [
"source",
"command",
"runtime",
"expected_output"
]
},
"formal_statement": null,
"source": {
"url": "https://cs.uwaterloo.ca/journals/JIS/VOL7/Haanpaa/haanpaa.html",
"locator": "Elementary counting and the exact replay in dpb101-artifact-eighteen-point-cover-check"
},
"models": [],
"relations": [
{
"slug": "R218",
"title": "Exact replay of the 18-element product basis",
"object_type": "artifact",
"relation": "evidences",
"direction": "incoming"
},
{
"slug": "R219",
"title": "The exact value at order 100 remains open in this audit",
"object_type": "attempt",
"relation": "informs",
"direction": "incoming"
},
{
"slug": "distinct-product-basis-f101",
"title": "distinct product basis f101",
"object_type": "problem",
"relation": "recorded_for",
"direction": "outgoing"
}
]
}7Provenance
View source, identifiers, and projection details
- Project
- distinct-product-basis-f101
- Locator
- Elementary counting and the exact replay in dpb101-artifact-eighteen-point-cover-check
- License
- CC0-1.0
- Contributors
- TheoremDB entry research, 2026-07-24
- Source
- cs.uwaterloo.ca ↗
- Public record
- R220
- Stable alias
- dpb101-claim-certified-interval-15-18
- Projection
- Reproduction fields are derived from the immutable record.
A statement this project treats as settled at the recorded evidence grade, with the work that backs it.