Zulip Chat Archive
Stream: Type theory
Topic: Indexed QPF
Palalansoukî (Nov 08 2025 at 08:58):
QPF.Fix provides a fixed point of functor F. Can we extend this to obtain (potentially infinite) fixed points, indexed by some type? That is, by assuming appropriate conditions for F, can we properly define a constructor and destructor as follows?
variable {ι : Type u} {F : (ι → Type v) → (ι → Type v)} [IndexedQPF F]
def Fix (F : (ι → Type v) → (ι → Type v)) : ι → Type v := sorry
def Fix.mk : (i : ι) → F (Fix F) i → Fix F i := sorry
def Fix.dest : (i : ι) → Fix F i → F (Fix F) i := sorry
Last updated: Dec 20 2025 at 21:32 UTC