Gysin #965
Gysin #965
Conversation
|
some assumptions can be weakened. Converting to draft for now |
# Conflicts: # Cubical/Cohomology/EilenbergMacLane/Base.agda # Cubical/Cohomology/EilenbergMacLane/EilenbergSteenrod.agda
| substIso B p = pathToIso (cong B p) | ||
|
|
||
| substEquiv' : ∀ {ℓ ℓ'} {A : Type ℓ} (B : A → Type ℓ') {x y : A} (p : x ≡ y) → B x ≃ B y | ||
| substEquiv' B p = isoToEquiv (substIso B p) |
There was a problem hiding this comment.
This seems like a roundabout way to define this? Can't you use the one without the prime that's already in the library?
There was a problem hiding this comment.
I don't remember why I need this but I can imagine a it being more useful than the one already in the lib. The one in the lib doesn't have an explicitly defined inverse (it's an isEquiv proof by J) which I want to remember was causing issues. But maybe I could add a comment?
There was a problem hiding this comment.
I seem to recall that we had different proofs of this before...
There was a problem hiding this comment.
So maybe move it so that it's next to substEquiv and add a comment explaining that the inverse gets more direct this way
There was a problem hiding this comment.
Couldn't move it next to it due to it needing pathToIso, but I added a comment.
| substIso B p = pathToIso (cong B p) | ||
|
|
||
| substEquiv' : ∀ {ℓ ℓ'} {A : Type ℓ} (B : A → Type ℓ') {x y : A} (p : x ≡ y) → B x ≃ B y | ||
| substEquiv' B p = isoToEquiv (substIso B p) |
There was a problem hiding this comment.
So maybe move it so that it's next to substEquiv and add a comment explaining that the inverse gets more direct this way
|
Should be ok now @mortberg |
|
Great! Will merge once the CI is happy |
* done * stuff * almost * done (not clean) * done * generalisation * minor * changes * minor * Update Cubical/Foundations/Transport.agda --------- Co-authored-by: Anders Mörtberg <[email protected]>
The Thom isomorphism and Gysin sequence for cohomology with coefficients in a commutative ring.
Depends on #955 and #954.