Zulip Chat Archive
Stream: Is there code for X?
Topic: Irreflexive Ne ∧ Symmetric Ne
Snir Broshi (Oct 13 2025 at 21:54):
For Eq there's docs#eq_equivalence, but for Ne I couldn't find proofs that it's irreflexive and symmetric.
Ruben Van de Velde (Oct 13 2025 at 21:59):
As theorems or instances of a particular class?
Ruben Van de Velde (Oct 13 2025 at 21:59):
@loogle Irreflexive
loogle (Oct 13 2025 at 21:59):
:search: Irreflexive, InvImage.irreflexive, and 11 more
Ruben Van de Velde (Oct 13 2025 at 22:00):
Yeah, nothing much there
Snir Broshi (Oct 13 2025 at 22:01):
For instances theres docs#IsIrrefl and docs#IsSymm, but those don't exist for docs#Ne either
Snir Broshi (Oct 13 2025 at 22:05):
If I add this, should I add the class version (IsIrrefl, IsSymm) or the prop version (Irreflexive, Symmetric)?
Eq has both IsEquiv and Equivalence, Iff has only IsEquiv, and Relation.EqvGen has only Equivalence.
Why do we need both versions of all these properties of relations?
Snir Broshi (Oct 13 2025 at 23:19):
Apparently there's also docs#Std.Irrefl and docs#Std.Symm, sigh
Snir Broshi (Oct 13 2025 at 23:20):
but I found docs#Ne.irrefl and docs#Ne.symm, which are close to what i asked
theorem foo1 {α : Type*} : Irreflexive (α := α) Ne := fun _ ↦ Ne.irrefl
theorem foo2 {α : Type*} : Symmetric (α := α) Ne := fun _ _ ↦ Ne.symm
Ruben Van de Velde (Oct 14 2025 at 06:21):
Yeah, I'm not sure what the status of these structures is
Last updated: Dec 20 2025 at 21:32 UTC