fact: Definition fset_car_setoid A `{FSet A} : Setoid A := setoidmor_a singleton.
imports: MathClasses.theory.lattices MathClasses.varieties.monoids MathClasses.implementations.bool MathClasses.implementations.list_finite_set MathClasses.orders.lattices MathClasses.interfaces.abstract_algebra MathClasses.interfaces.finite_sets MathClasses.interfaces.orders