Add AGENTS.md

.github/workflows/Nuget.yml

@@ -1,11 +1,6 @@
-name: 'Upload to MyGet and NuGet'
-
-run-name: ${{ github.event_name == 'push' && 'Upload to MyGet' || 'Upload to NuGet' }}
+name: 'Upload to NuGet'
 
 on:
-  push:
-    branches:
-      - master
   release:
     types: [published]
 
@@ -23,57 +18,39 @@ jobs:
 
       - uses: actions/checkout@v6
 
-      - name: 'Determine version and target'
+      - name: 'Determine version'
         id: version
         run: |
-          if [[ "${{ github.event_name }}" == "push" ]]; then
-            # MyGet versioning
-            commithash=$(git rev-parse --short HEAD)
-            currtime=$(date +%s)
-            echo "commit hash is $commithash"
-            echo "time is $currtime"
-            version=10.0.0-master-$currtime-$commithash
-            echo "version is $version"
-            echo "version=$version" >> $GITHUB_OUTPUT
-            echo "apikey=${{ secrets.MYGET_KEY }}" >> $GITHUB_OUTPUT
-            echo "source=myget" >> $GITHUB_OUTPUT
-            echo "target=MyGet" >> $GITHUB_OUTPUT
-          else
-            # NuGet versioning from release tag
-            tagname="${{ github.event.release.tag_name }}"
-
-            # Validate tag name exists
-            if [[ -z "$tagname" ]]; then
-              echo "Error: Release tag name is empty"
-              exit 1
-            fi
-
-            # Remove 'v' prefix if present (e.g., v1.0.0 -> 1.0.0)
-            version="${tagname#v}"
-            echo "Release tag is $tagname"
-            echo "Package version is $version"
-
-            # Validate version format (SemVer 2.0.0: X.Y.Z[-prerelease][+build])
-            if [[ ! "$version" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-[0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*)?(\+[0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*)?$ ]]; then
-              echo "Error: Invalid version format '$version'."
-              echo "Expected semantic version (e.g., 1.0.0, 1.0.0-beta.1, 1.0.0+build.123)"
-              exit 1
-            fi
-
-            echo "version=$version" >> $GITHUB_OUTPUT
-            echo "apikey=${{ secrets.NUGET_KEY }}" >> $GITHUB_OUTPUT
-            echo "source=nuget.org" >> $GITHUB_OUTPUT
-            echo "target=NuGet" >> $GITHUB_OUTPUT
+          tagname="${{ github.event.release.tag_name }}"
+
+          # Validate tag name exists
+          if [[ -z "$tagname" ]]; then
+            echo "Error: Release tag name is empty"
+            exit 1
           fi
-
+
+          # Remove 'v' prefix if present (e.g., v1.0.0 -> 1.0.0)
+          version="${tagname#v}"
+          echo "Release tag is $tagname"
+          echo "Package version is $version"
+
+          # Validate version format (SemVer 2.0.0: X.Y.Z[-prerelease][+build])
+          if [[ ! "$version" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-[0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*)?(\+[0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*)?$ ]]; then
+            echo "Error: Invalid version format '$version'."
+            echo "Expected semantic version (e.g., 1.0.0, 1.0.0-beta.1, 1.0.0+build.123)"
+            exit 1
+          fi
+
+          echo "version=$version" >> $GITHUB_OUTPUT
+
       - name: 'Pack and publish AngouriMath'
         run: |
           cd Sources/AngouriMath
           dotnet restore AngouriMath.csproj
           dotnet build AngouriMath.csproj -c release
           dotnet pack AngouriMath.csproj -c release -p:PackageVersion=${{ steps.version.outputs.version }}
           cd bin/release
-          dotnet nuget push AngouriMath.${{ steps.version.outputs.version }}.nupkg --api-key ${{ steps.version.outputs.apikey }} --source "${{ steps.version.outputs.source }}"
+          dotnet nuget push AngouriMath.${{ steps.version.outputs.version }}.nupkg --api-key ${{ secrets.NUGET_KEY }} --source nuget.org
 
       - name: 'Pack and publish AngouriMath.FSharp'
         run: |
@@ -82,7 +59,7 @@ jobs:
           dotnet build -c Release
           dotnet pack -c Release -p:PackageVersion=${{ steps.version.outputs.version }}
           cd bin/Release
-          dotnet nuget push AngouriMath.FSharp.${{ steps.version.outputs.version }}.nupkg --api-key ${{ steps.version.outputs.apikey }} --source "${{ steps.version.outputs.source }}"
+          dotnet nuget push AngouriMath.FSharp.${{ steps.version.outputs.version }}.nupkg --api-key ${{ secrets.NUGET_KEY }} --source nuget.org
 
       - name: 'Pack and publish AngouriMath.Interactive'
         run: |
@@ -91,7 +68,7 @@ jobs:
           dotnet build -c Release
           dotnet pack -c Release -p:PackageVersion=${{ steps.version.outputs.version }}
           cd bin/Release
-          dotnet nuget push AngouriMath.Interactive.${{ steps.version.outputs.version }}.nupkg --api-key ${{ steps.version.outputs.apikey }} --source "${{ steps.version.outputs.source }}"
+          dotnet nuget push AngouriMath.Interactive.${{ steps.version.outputs.version }}.nupkg --api-key ${{ secrets.NUGET_KEY }} --source nuget.org
 
       - name: 'Pack and publish AngouriMath.Terminal'
         run: |
@@ -100,4 +77,4 @@ jobs:
           dotnet build -c Release
           dotnet pack -c Release -p:PackageVersion=${{ steps.version.outputs.version }}
           cd bin/Release
-          dotnet nuget push AngouriMath.Terminal.${{ steps.version.outputs.version }}.nupkg --api-key ${{ steps.version.outputs.apikey }} --source "${{ steps.version.outputs.source }}"
+          dotnet nuget push AngouriMath.Terminal.${{ steps.version.outputs.version }}.nupkg --api-key ${{ secrets.NUGET_KEY }} --source nuget.org

AGENTS.md

@@ -0,0 +1,158 @@
+# AGENTS.md
+
+For AI agents working on AngouriMath. Humans: [CONTRIBUTING.md](CONTRIBUTING.md) is yours, and
+everything below applies to you too.
+
+AngouriMath is a computer algebra system. The thing being built is *mathematics*, and the code is
+how it is expressed. Read this as instructions for doing mathematics well, using C# and F#.
+
+## The one rule everything else follows from
+
+**Be a mathematician first.** When mathematical correctness and backward compatibility disagree,
+correctness wins. A published API that returns the wrong answer is not an asset to preserve; it is
+a bug with users. Say so in the changelog, and change it.
+
+The same goes for convention. If mathematicians write it one way and the library writes it another,
+the library is wrong — even where the library's way is defensible in isolation. `arcsinh` is not a
+thing; the inverse of `sinh` is an *area*, not an arc, so it is `arsinh` (#687). Follow the notation
+of the people who use the subject, not the notation that was easiest to parse.
+
+**Consistency is the point.** [#497](https://github.com/asc-community/AngouriMath/issues/497), the
+2.0 paper, names inconsistency as the central defect: *"one may find it inconsistent in a lot of
+places in API, behaviour, and internal structure of code."* A rule that fires for `sin` but not
+`tan`, a limit that works from both sides but not from one, an evaluation that holds precision for
+large numbers and drops it for small — each is a bug even when every individual case is defensible.
+When you fix something, ask what else is the same shape, and fix that too, or write down why not.
+
+## Not answering is a legitimate answer. Answering wrongly is not.
+
+The most important distinction in this codebase:
+
+| result | means |
+|---|---|
+| unevaluated (`Limitf`, the original expression back) | "I could not settle this" |
+| `NaN` | "**this does not exist**" |
+| a value | "this is the value" |
+
+These are three different claims and they are not interchangeable. Returning `NaN` for a limit you
+merely failed to compute is a *wrong answer*, not a graceful failure — it tells the caller the limit
+does not exist. Returning an unevaluated node is honest.
+
+So, in order of preference: right answer > no answer > slow answer > wrong answer. A wrong answer is
+worse than a hang, because a hang is visible.
+
+## Verify the mathematics, not the string
+
+Never assert on printed form unless the printed form *is* the bug. Assert the property:
+
+- an integral: differentiate it back and compare to the integrand
+- a root: substitute it into the equation
+- an identity: subtract the two sides and simplify to zero
+- a limit: check it against the value at nearby points, or a series
+
+A string comparison passes for `2*x` and fails for `x*2`, which tells you nothing about whether the
+answer is right. `Sources/Tests/UnitTests/Common/IssueRegressionTest.cs` is where issue regressions
+go, named for the issue.
+
+**Reproduce on a stock `master` build before claiming anything is broken.** More than one confident
+report here has turned out to describe behaviour that was never broken.
+
+## Aim high
+
+The ambition is to answer the hard problems: olympiad and competition algebra, calculus and number
+theory; the integrals and limits that need real machinery rather than pattern tables; the questions
+where the honest current answer is "unevaluated". Concretely, that means things like Risch for
+integration, a proper polynomial layer (multivariate GCD, resultants, factorisation) which most of
+the open simplification issues sit behind, and quantifier elimination for inequalities.
+
+Measure against a corpus of problems with known answers, and report **wrong / error / timeout**
+counts alongside the solved count. A change that solves one more problem and introduces one wrong
+answer is a regression. Compare against SymPy, Mathematica, or a textbook — being different from
+SymPy is not automatically being wrong, but it is always worth explaining.
+
+## Keep up with the mathematics
+
+Algorithms here are decades of literature deep, and the good ones are written down. Before inventing
+a procedure, find out whether it has a name:
+
+- **SymPy** (`sympy/`) — readable reference implementations of Risch, Gruntz, Gröbner, and much else,
+  with the papers cited in the docstrings. The single most useful cross-check.
+- **Mathematica / Wolfram Alpha, Maxima, SageMath** — for deciding what the right answer *is*.
+- **DLMF** (dlmf.nist.gov) — the authority on special-function identities and branch cuts.
+- **OEIS** — for recognising an integer sequence.
+- **arXiv math.AC / cs.SC**, the *Journal of Symbolic Computation*, and the ISSAC proceedings — where
+  new symbolic-computation algorithms appear.
+- **Gruntz's thesis** for limits, **Bronstein's _Symbolic Integration I_** for integration,
+  **_Modern Computer Algebra_** (von zur Gathen & Gerhard) for the polynomial layer.
+
+Branch cuts deserve a specific warning: `arcsin`, `log`, and fractional powers disagree between
+conventions, and C99, .NET, Python and Mathematica do not all agree. Decide deliberately, cite the
+convention, and test the disagreeing points.
+
+## Working practice
+
+**Branch first, always.** Never commit a feature or a fix straight to `master`, even with write
+access. One branch per change, each independently mergeable, cut from `master`.
+
+```
+fix/<what-was-wrong>        fix/vanishing-denominator
+feat/<what-is-new>          feat/gruntz
+perf/<what-got-faster>      perf/limit-memoisation
+docs/<what-is-documented>   docs/agents-md
+chore/<housekeeping>        chore/drop-myget
+```
+
+Then:
+
+1. Write the failing test first, and check it fails for the reason you think.
+2. Fix it. Prefer the smaller change with the smaller blast radius.
+3. Run everything: `dotnet test Sources/Tests/UnitTests`,
+   `dotnet test Sources/Tests/FSharpWrapperUnitTests`.
+4. If an existing test now fails, decide honestly which it is — the answer got better, the test was
+   pinning a fudge, or you broke something — and say which in the commit message. Never loosen an
+   assertion without writing down why.
+5. Open a PR. State what was wrong, why the fix is right, and what you measured.
+
+`TreatWarningsAsErrors` is on and there are custom analyzers; a static field needs
+`[ConstantField]`, `[ThreadStatic]` or `[ConcurrentField]`.
+
+## Write for the reader, briefly
+
+Comments explain **why**, not what — the code says what. The reader is a mathematician six months
+from now wondering whether a line can be deleted. Tell them what breaks if it is.
+
+```csharp
+// (x - a)^k is positive on the right whatever k is, and on the left takes the sign of
+// (-1)^k, so approaching from the left at an odd order turns the sign around.
+```
+
+Be concise. Do not narrate your own process, and **do not record your mistakes, wrong turns or
+retracted diagnoses in code, commit messages or documentation.** Those belong in the issue tracker,
+where they are searchable and where someone hitting the same wall will find them. What belongs in
+the code is the conclusion and the reason it holds. A measurement that justifies a constant is a
+reason; a story about how you arrived at it is not.
+
+Cite issues by full URL in code comments (`https://github.com/asc-community/AngouriMath/issues/557`),
+since a bare `#557` means nothing outside GitHub. `#557` is fine in PR titles and bodies.
+
+## Where the work is
+
+Good entry points, roughly by depth:
+
+- **Simplification consistency** — [#531](https://github.com/asc-community/AngouriMath/issues/531),
+  [#557](https://github.com/asc-community/AngouriMath/issues/557),
+  [#415](https://github.com/asc-community/AngouriMath/issues/415). Rules that fire in one arrangement
+  and not another.
+- **Limits** — [#596](https://github.com/asc-community/AngouriMath/issues/596),
+  [#536](https://github.com/asc-community/AngouriMath/issues/536). `0^0` and `oo^0` have no rule
+  where `1^oo` has one; piecewise has none at all.
+- **Numerics** — [#602](https://github.com/asc-community/AngouriMath/issues/602). Precision that
+  holds at one scale and not another.
+- **Solving** — [#629](https://github.com/asc-community/AngouriMath/issues/629),
+  [#475](https://github.com/asc-community/AngouriMath/issues/475),
+  [#381](https://github.com/asc-community/AngouriMath/issues/381). Diophantine equations and
+  characteristic polynomials both want the polynomial layer.
+- **The polynomial layer itself** — multivariate GCD, resultants, factorisation. Large, and most of
+  the above sits behind it.
+- **[#497](https://github.com/asc-community/AngouriMath/issues/497), AngouriMath 2.0** — the design
+  paper. If you are proposing something structural, propose it there.

README.md

@@ -58,18 +58,6 @@ Note, that all tests and builds are tested for the following three operating sys
 | Terminal | <a href="https://www.nuget.org/packages/AngouriMath.Terminal"><img alt="Nuget (with prereleases)" src="https://img.shields.io/nuget/vpre/AngouriMath.Terminal?color=blue&label=NuGet&logo=nuget&style=flat-square"></a> | <a href="https://www.nuget.org/packages/AngouriMath.Terminal"><img alt="Nuget" src="https://img.shields.io/nuget/v/AngouriMath.Terminal?color=blue&label=NuGet&logo=nuget&style=flat-square"></a> | <a href="https://www.nuget.org/packages/AngouriMath.Terminal"><img alt="Nuget" src="https://img.shields.io/nuget/dt/AngouriMath.Terminal?color=darkblue&label=Downloads&style=flat-square"></a> |
 | C++ | <img alt="GitHub release (latest SemVer including pre-releases)" src="https://img.shields.io/github/v/release/asc-community/AngouriMathLab?include_prereleases&label=GH%20Releases"> | WIP | WIP |
 
-There are also latest-master versions (updated on every push to master) on [MyGet](https://www.myget.org/feed/Packages/angourimath):
-| MyGet | Downloads |
-|-------|-----------|
-| [![MyGet (with prereleases)](https://img.shields.io/myget/angourimath/vpre/AngouriMath?label=AngouriMath)](https://www.myget.org/feed/angourimath/package/nuget/AngouriMath) | ![MyGet](https://img.shields.io/myget/angourimath/dt/AngouriMath?label=Downloads) |
-| [![MyGet (with prereleases)](https://img.shields.io/myget/angourimath/vpre/AngouriMath.FSharp?label=AngouriMath.FSharp)](https://www.myget.org/feed/angourimath/package/nuget/AngouriMath.FSharp) | ![MyGet](https://img.shields.io/myget/angourimath/dt/AngouriMath.FSharp?label=Downloads) |
-| [![MyGet (with prereleases)](https://img.shields.io/myget/angourimath/vpre/AngouriMath.Interactive?label=AngouriMath.Interactive)](https://www.myget.org/feed/angourimath/package/nuget/AngouriMath.Interactive) | ![MyGet](https://img.shields.io/myget/angourimath/dt/AngouriMath.Interactive?label=Downloads) |
-| [![MyGet (with prereleases)](https://img.shields.io/myget/angourimath/vpre/AngouriMath.Terminal?label=AngouriMath.Terminal)](https://www.myget.org/feed/angourimath/package/nuget/AngouriMath.Terminal) | ![MyGet](https://img.shields.io/myget/angourimath/dt/AngouriMath.Terminal?label=Downloads) |
-
-Source to install from MyGet:
-```
-https://www.myget.org/F/angourimath/api/v3/index.json  
-```
 
 #### Other info
 | Website | Stars | License |

Sources/NuGet.Config

@@ -6,6 +6,5 @@
     <add key="dotnet-public" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json" />
     <add key="dotnet-experimental" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-experimental/nuget/v3/index.json" />
     <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
-    <add key="myget" value="https://www.myget.org/F/angourimath/api/v3/index.json" />
   </packageSources>
 </configuration>