Coqでの古典集合
mathcomp
外包的記法
Inductive Fruits : Type :=
| Apple
| Orange
| PineApple
| Mango.
内包的記法
Definition IsMyFruits (fruits : Fruits) : Prop :=
match fruits with
| Apple => True
| Orange => True
| Mango => True
| _ => False
end.