[FBumann]

Prompt: Should we put sth on main directly? As an example? […] Yes

Note

The following content was generated by AI.

What this changes

The "Tests" section of the relations reference gains a worked example. A variable masked by a bare relation, where: connection, has a column only at the listed (generator, bus) pairs, so a balance adds up only the wired generators.

relations:
  connection: { key: [generator, bus], missing: absent } # the pairs that are wired
variables:
  flow:
    dims: [generator, bus, snapshot]
    where: connection
    bounds: { lower: 0 }
constraints:
  balance:
    dims: [bus, snapshot]
    expression: sum(flow, over=generator) == load

Method, gates, and what was not done

Method. The page's full YAML block was loaded with python -m mathspec check. The two equations under it are copied from to_markdown of that spec, with \left( g,\ b \right) written as (g, b).

Gates. pixi is not installed in this container, so the gates ran in a uv venv on Python 3.13, with zensical==0.0.63. They ran on origin/main at 13fba32, plus this commit.

• pytest -q -n auto: 3063 passed, 3 skipped.
• python -m zensical build --strict: no issues.
• prettier --check and typos --force-exclude on the page: clean.
• compile-tex was not run, because the container has no tectonic. The PR changes no spec in its corpus.

Not done. On main, the only examples of a relation as a mask were on constraints: looked_up on the linear-maps page, and connected on the notation page. This adds the variable case only. A parameter masked by a relation is #945, which is stacked on #894 and does not touch this page.

Why

#935 asks how a quantity over several dimensions can be limited to the valid combinations. For a variable, the language can already say this. The page now shows it, so #935 and #945 can link to main.

---

Generated by Claude Code

[read-the-docs-community]

Documentation build overview

📚 mathspec | 🛠️ Build #35336488 | 📁 Comparing 96bf12b against latest (13fba32)

  🔍 Preview build  

2 files changed

± reference/changelog/index.html
± reference/language/relations/index.html