エロ漫画か何かの1シーン https://twitter.com/t4nsu/status/502612362915229697/photo/1 が論理パズルだったのでAlloyで解こうとしてみた

manga.als

abstract sig Person {
	anal_sex_with : set Person,
	sex_with : set Person,
	female_sex_with : set Person,
	fellatio_with : set Person
}

sig Male in Person { }

fun Female : set Person { 	Person - Male }
// pred Female[x:Person] { x not in Male }

one sig A, B, C, D, E, F, G, H extends Person { }

one sig Akira, Shinya, Hiroshi, Chiaki, Saki, Yuri, Mika, Reina in Person { }

pred Foo {
	// general assumption
	(B + C + F + H) = Male
	(Akira + Shinya + Hiroshi + Chiaki) = Male
	(Saki + Yuri + Mika + Reina) = Female
	Person.~sex_with in Male
	Person.sex_with in Female
	Person.female_sex_with in Female
	female_sex_with = ~female_sex_with
	Person.~fellatio_with in Male
	no (iden & anal_sex_with)
	no (iden & sex_with)
	no (iden & female_sex_with)
	no (iden & fellatio_with)
	// A's hint
	(A.female_sex_with + A) = Female
	// B's hint
	no (B.sex_with & Mika)
	// C's hint
	(Mika + Chiaki) in C.anal_sex_with
	no C.sex_with
	// D's hint
	D.~fellatio_with = Shinya
	D.~female_sex_with = Yuri // here
	D.~(sex_with+anal_sex_with) = Hiroshi
	Reina in Hiroshi.(sex_with+anal_sex_with)
	// E's hint
	not E = Saki // here
	no E.~fellatio_with
	no Saki.~fellatio_with
	Reina in E.female_sex_with
	// F's hint
	Saki in F.sex_with
	Chiaki in F.anal_sex_with
	// G's hint
	Saki in Akira.sex_with
	// H's hint
	Chiaki = B
	Mika in H.fellatio_with
}

run Foo for 3