Mitsch Order #1024
Open
Mitsch Order #1024
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
gap/attributes/attr.gi
Outdated
| @@ -1052,6 +1052,188 @@ function(S) | |||
| end; | |||
| end); | |||
|
|
|||
| InstallMethod(KernelContainment, | |||
There was a problem hiding this comment.
Please:
- move this to
gap/elements/transf.g* - add tests
- add doc
- rename to
IsRefinementKernelOfTransformation - improve the error message using the format: "where, what went wrong, what was expected, and what was found"
| deg := DegreeOfTransformationSemigroup(S); | ||
| return | ||
| function(x, y) | ||
| # Only returns the correct answer if y is a regular element |
There was a problem hiding this comment.
Add check that y is regular.
Also what happens if x or y not in S?
gap/attributes/attr.gi
Outdated
| return out; | ||
| end); | ||
|
|
||
| InstallMethod(MitschOrderOfTransformationSemigroup, |
There was a problem hiding this comment.
Remove this, unless it is actually much faster.
Co-authored-by: James Mitchell <james-d-mitchell@users.noreply.github.com>
Co-authored-by: James Mitchell <james-d-mitchell@users.noreply.github.com>
Co-authored-by: James Mitchell <james-d-mitchell@users.noreply.github.com>
Co-authored-by: James Mitchell <james-d-mitchell@users.noreply.github.com>
fingolfin
reviewed
Sep 5, 2024
Comment on lines
+1063
to
+1072
| exists := false; | ||
| for i in [1 .. Size(class)] do | ||
| if class[i] ^ a = class[i] ^ b then | ||
| exists := true; | ||
| break; | ||
| fi; | ||
| od; | ||
| if not exists then | ||
| return false; | ||
| fi; |
There was a problem hiding this comment.
Not saying this is better, but I think you could also write it like this (assuming class is an iterable object):
Suggested change
| exists := false; | |
| for i in [1 .. Size(class)] do | |
| if class[i] ^ a = class[i] ^ b then | |
| exists := true; | |
| break; | |
| fi; | |
| od; | |
| if not exists then | |
| return false; | |
| fi; | |
| if ForAll(class, x -> x ^ a <> x ^ b) then | |
| return false; | |
| fi; |
fingolfin
reviewed
Sep 5, 2024
Comment on lines
+1101
to
+1102
| return ForAny(Elements(S), s -> x = x * s and x = y * s) and | ||
| ForAny(Elements(S), t -> t * y = x and t * x = x); |
There was a problem hiding this comment.
Aren't semigroups iterable? Because if they are, can't you just write
Suggested change
| return ForAny(Elements(S), s -> x = x * s and x = y * s) and | |
| ForAny(Elements(S), t -> t * y = x and t * x = x); | |
| return ForAny(S, s -> x = x * s and x = y * s) and | |
| ForAny(S, t -> t * y = x and t * x = x); |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Add methods for finding the Mitsch order of a semigroup