feat(language): a sos block says along, not over, for the dimension its set runs along

[FBumann]

Prompt: "sos: over → along rename is right" … "I think we should land the "along" change for sos on main independently!"

Note

The following content was generated by AI.

What this changes

A sos: block names the dimension its set runs along as along:, the word piecewise: uses for the same thing. over: on a sos: block is refused, with no alias. The same rename in #630 is lifted out so it lands on its own.

sos:
  pick_one_size:
    variable: build
    along: size # was: over
    type: 1

Breaking for the file language: sos: … over: no longer loads. Every file with a set renames the key.

Where the spelling moved

Reader	Change
SosBlock.over, SosDeclaration.over	now along
the load-time refusal	Sos 's': along 'h' is not a dim of variable 'p'
the separability verdict	"is a set along d, which a window would cut"
the sos: block a piecewise: expansion writes	keyed along
the schema, the notation page	regenerated
the fixtures under tests/expand/set-*, the golden model, the docs examples	renamed

The over: of a piecewise: block is untouched here; #630 renames it as part of its own design.

Gates, and what was not run

Gate	Result
pytest -q -n auto	1598 passed, 5 skipped, the docs tests included
ruff check, ruff format --check	clean
pyrefly check	0 errors
prettier --check on the three changed pages	clean
schema, golden output, notation page	regenerated; the typeset output has no diff
compile-tex, docs-build	not run here: no tectonic, and the proxy refuses docs.python.org; Read the Docs builds the head

Why

piecewise: says along: for the dimension a curve runs along, and a set runs along a dimension the same way. One word for one idea. Landing it alone keeps #630 to the piecewise feature.

🤖 Generated with Claude Code

https://claude.ai/code/session_015h57WkBDnpxrknuJ5zZy9F

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Generated by Claude Code

[read-the-docs-community]

Documentation build overview

📚 math-spec | 🛠️ Build #34718558 | 📁 Comparing f2a1d7c against latest (12ccb67)

  🔍 Preview build  

8 files changed · ± 8 modified

± Modified

• howto/see-an-expansion/index.html
• reference/notation/index.html
• reference/language/piecewise/index.html
• reference/math_spec/lowering/index.html
• reference/math_spec/model/index.html
• reference/math_spec/program/index.html
• reference/math_spec/separability/index.html
• reference/math_spec/sos/index.html