Preparations for defining operations on Finset. #
The operations here ignore multiplicities,
and preparatory for defining the corresponding operations on Finset.
finset insert #
ndinsert a s is the lift of the list insert operation. This operation
does not respect multiplicities, unlike cons, but it is suitable as
an insert operation on Finset.
Equations
- Multiset.ndinsert a s = Quot.liftOn s (fun l => ↑(List.insert a l)) (_ : ∀ (x x_1 : List α), Setoid.r x x_1 → Quot.mk Setoid.r (List.insert a x) = Quot.mk Setoid.r (List.insert a x_1))
Instances For
finset union #
ndunion s t is the lift of the list union operation. This operation
does not respect multiplicities, unlike s ∪ t, but it is suitable as
a union operation on Finset. (s ∪ t would also work as a union operation
on finset, but this is more efficient.)
Equations
- One or more equations did not get rendered due to their size.
Instances For
finset inter #
ndinter s t is the lift of the list ∩ operation. This operation
does not respect multiplicities, unlike s ∩ t, but it is suitable as
an intersection operation on Finset. (s ∩ t would also work as a union operation
on finset, but this is more efficient.)
Equations
- Multiset.ndinter s t = Multiset.filter (fun x => x ∈ t) s