files / problems / projective-plane-order-twelve / compute / certs / type_classification.json
{
"checks": [
{
"name": "v=157",
"ok": true,
"detail": "v=157"
},
{
"name": "v mod 2",
"ok": true,
"detail": "157%2=1"
},
{
"name": "v mod 3",
"ok": true,
"detail": "157%3=1"
},
{
"name": "bruck-ryser silent",
"ok": true,
"detail": "12%4=0"
},
{
"name": "det identity integer",
"ok": true,
"detail": "13*12^78"
},
{
"name": "12 even",
"ok": true,
"detail": ""
},
{
"name": "12 not square",
"ok": true,
"detail": ""
},
{
"name": "2 divides n (elation order)",
"ok": true,
"detail": "elation group order | n"
},
{
"name": "n not 2 mod 4",
"ok": true,
"detail": "the n\u22612 (mod 4) involution ban is silent"
},
{
"name": "possible f start at 1",
"ok": true,
"detail": "[1, 4, 7, 10, 13, 16]"
},
{
"name": "true homology f=14 forbidden by v",
"ok": true,
"detail": "14%3=2"
},
{
"name": "true homology 3 divides n-1",
"ok": true,
"detail": "11%3=2"
},
{
"name": "no generalized homology of order 3",
"ok": true,
"detail": "survivors=[]"
},
{
"name": "Fano line extra points",
"ok": true,
"detail": "10%3=1"
},
{
"name": "PG(2,3) line extra points ok",
"ok": true,
"detail": "9%3=0"
},
{
"name": "g.e. candidates",
"ok": true,
"detail": "f in [1, 4, 7, 10, 13]; f=13 is the 1981 true-elation case"
}
],
"all_ok": true,
"remaining": {
"order_2": [
"involutory elation (unique Baer type)"
],
"order_3": [
"planar with Fix \u2245 PG(2,3)",
"generalized elation with f in {1,4,7,10}"
],
"excluded_here_by_divisibility": [
"true homology of order 3",
"generalized homology of order 3",
"planar with Fix \u2245 PG(2,2)"
],
"excluded_in_literature": [
"true elation of order 3 (Janko\u2013van Trung 1981)",
"any |G| not in {1,2,3} (Akiyama\u2013Suetake\u2013Tanaka 2023)"
]
}
}