Pullback of rational functions along strict transforms #2681
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I introduced a type for lazy composite maps of covered schemes. These should be useful in many places and I needed them to facilitate the moving around of elements of the function fields. |
Codecov Report
Additional details and impacted files@@ Coverage Diff @@
## master #2681 +/- ##
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- Coverage 72.46% 72.31% -0.15%
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Files 441 441
Lines 62009 62494 +485
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+ Hits 44933 45191 +258
- Misses 17076 17303 +227
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| # complements in `U_sub` and `V_sub` also is. | ||
| k = findfirst(x->has_ancestor(y->y===U_amb, codomain(inc_dom_cov[x])), patches(domain(inc_dom_cov))) | ||
| U_sub = patches(domain(inc_dom_cov))[k] | ||
| iso_U_sub = _flatten_open_subscheme(U_sub, domain(inc_dom_cov[U_sub])) |
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what does this do and why do you do it?
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line 192 is deprecated and superfluous. Did you mean that? In that case: Thanks for catching!
| # to do the following. | ||
| # - Find a `patch` `U_sub` of the `domain` of `inc_dom_cov` for which | ||
| # inc_cod : U_sub -> W has a codomain `W` which has `U_amb` as an | ||
| # ancestor. Since `U_amb` is one of the `affine_charts` of `X`, this will work. |
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Why is U_amb a chart of X? It seems to me that it is a chart of Y?
What is the domain and codomain of p_iso? (i.e. does it point in the same direction as p? or the opposite one?)
| map_string = "$(domain(f)) -> " | ||
| for i in 2:length(maps(f)) | ||
| map_string = map_string * "$(domain(map(f)[i])) -> " | ||
| end | ||
| map_string = map_string * "$(codomain(map(f)[end]))" | ||
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| print(io, "Composition of ", map_string) |
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No need to print to an intermediate string
| map_string = "$(domain(f)) -> " | |
| for i in 2:length(maps(f)) | |
| map_string = map_string * "$(domain(map(f)[i])) -> " | |
| end | |
| map_string = map_string * "$(codomain(map(f)[end]))" | |
| print(io, "Composition of ", map_string) | |
| print(io, "Composition of ", map_string) | |
| print(io, domain(f), " -> ") | |
| for i in 2:length(maps(f)) | |
| print(io, domain(map(f)[i]), " -> ") | |
| end | |
| print(io, codomain(map(f)[end])) |
| end | ||
| end |
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| end | |
| end | |
| end | |
| print(io, Dedent()) | |
| end |
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Let's pray the CI completes this time. |
Needed for the fibration hopping in the Oscar book chapter.
@afkafkafk13 : There is one important change in here: I derived
BlowupMorphismfromAbsCoveredSchemeMorphism. I know we talked about this some months ago and you had reasons to decide against this. But I didn't remember these reasons and, at least for me, within the last weeks it became more and more clear that it should really be like this.Let me know if you still have objections against this.