base/eqalignno-to-align-env

Level

AuthoringFaithfulCorpusEquivEvery profile applies this rule; its output remains suitable for authoring.

Fidelity

readingPreserves notation, reading order, and structural roles.

Package

base

Source

base/authoring/plain_tex_matrix/eqalignno_to_align_env.rs (opens in new tab)

Triggers

\eqalignno command

Eliminates

\eqalignno command

Produces

align* environment; \tag command

Touches

\cr, \\, \newline commands

Rewrite patterns#

1. parenthesized-numeric-number\eqalignno{#1&#2&(#3)}\begin{align*} #1&#2 \tag{#3} \end{align*}
2. raw-numeric-number\eqalignno{#1&#2&#3}\begin{align*} #1&#2 \tag*{#3} \end{align*}
3. parenthesized-math-number\eqalignno{#1&#2&(#3)}\begin{align*} #1&#2 \tag{$#3$} \end{align*}
4. raw-math-number\eqalignno{#1&#2&#3}\begin{align*} #1&#2 \tag*{$#3$} \end{align*}
5. empty-number-cell\eqalignno{#1&#2&}\begin{align*} #1&#2 \end{align*}
6. missing-number-cell\eqalignno{#1&#2}\begin{align*} #1&#2 \end{align*}
7. final-row-terminator\eqalignno{#1&#2&(#3)\cr}\begin{align*} #1&#2 \tag{#3} \end{align*}
8. internal-empty-row\eqalignno{#1&#2&(#3)\cr\cr#4&#5&(#6)}\begin{align*} #1&#2 \tag{#3}\\\\#4&#5 \tag{#6} \end{align*}
9. linebreak-arguments\eqalignno{#1&#2&(#3)\\*[#4]}\begin{align*} #1&#2 \tag{#3}\\*[#4] \end{align*}
10. newline\eqalignno{#1&#2&(#3)\newline#4&#5&(#6)}\begin{align*} #1&#2 \tag{#3}\\#4&#5 \tag{#6} \end{align*}
11. leading-row-scripts\eqalignno{#1&#2&(#3)\cr_{#4}^{#5}#6&#7&(#8)}\begin{align*} #1&#2 \tag{#3}\\{}_{#4}^{#5}#6&#7 \tag{#8} \end{align*}

Examples#

Each example shows this rule applied in isolation. A complete normalization profile may make additional changes.

\eqalignno{F(x)&=\int_0^x f(t)\,dt&(1)\cr F'(x)&=f(x)&(2)\cr F''(x)&=f'(x)&(3)}

\begin{align*} F(x)&=\int_0^x f(t)\,dt \tag{1}\\ F'(x)&=f(x) \tag{2}\\ F''(x)&=f'(x) \tag{3} \end{align*}

Related rules#

Same family#

• ams/Bmatrix-env-to-brace-matrix Rewrite the fenced Bmatrix environment to explicit braces around a core matrix environment.
• ams/Vmatrix-env-to-Vert-matrix Rewrite the fenced Vmatrix environment to explicit double bars around a core matrix environment.
• ams/bmatrix-env-to-bracket-matrix Rewrite the fenced bmatrix environment to explicit brackets around a core matrix environment.
• ams/pmatrix-env-to-paren-matrix Rewrite the fenced pmatrix environment to explicit parens around a core matrix environment.
• ams/vmatrix-env-to-vert-matrix Rewrite the fenced vmatrix environment to explicit vertical bars around a core matrix environment.
• base/cases-to-cases-env Rewrite plain-TeX cases to the standard cases environment with row breaks.
• base/eqalign-to-aligned-env Rewrite eqalign to the standard aligned environment.
• base/matrix-to-matrix-env Rewrite plain-TeX matrix to the standard matrix environment with row breaks.
• base/pmatrix-to-pmatrix-env Rewrite plain-TeX pmatrix to the standard pmatrix environment with row breaks.
• physics/antidiagonalmatrix-to-admat Collapse antidiagonalmatrix to the shorter admat helper.
• physics/diagonalmatrix-to-dmat Collapse diagonalmatrix to the shorter dmat helper.
• physics/matrixdeterminant-to-mdet Collapse matrixdeterminant to the shorter mdet determinant helper.
• physics/bmqty-to-mqty Expand bmqty to the core mqty builder with bracket fence syntax.
• physics/mdet-to-vmqty Expand mdet to the vmqty determinant-style builder.
• physics/pmqty-to-mqty Expand pmqty to the core mqty builder with paren fence syntax.
• physics/zmat-to-xmat Expand zmat to the explicit xmat zero-filled builder.

Notes#

The second body-level AlignmentTab separates the third mathematical numbering cell; nested alignment tabs do not create new cells, and a row with more than three cells returns a normal transform error. Rows with a missing or empty number cell and actual empty rows get no tag, because \eqalignno never numbers rows automatically; the target is align* so no automatic numbers appear. A single complete outer parenthesis pair becomes \tag; otherwise retain the number verbatim with \tag*, without adding parentheses. Numeric patterns apply to ASCII-digit-only content after removal of that outer pair; all other numbering content retains its mathematical subtree inside a $...$ text-mode tag argument, including scripts, groups, fractions, text commands, and nested environments. Only a complete outer pair is removed, so (n)+(m) remains raw. Split only known body-level \cr, \\, and \newline; copy the original \\ star and optional spacing arguments, including \\*[2pt]. Remove exactly the artificial empty segment after a final terminator and omit a final default separator; retain final starred or spaced separators, consecutive internal empty rows, and explicitly terminated final empty rows. Transfer scripts and primes on a parsed separator to an empty base in the next row rather than to the preceding tag. Do not descend into explicit groups or nested environments when identifying separators.

Disable this rule#

TransformEngine(profile="corpus", disable_rules=["base/eqalignno-to-align-env"])

new TransformEngine({ profile: 'corpus', disableRules: ['base/eqalignno-to-align-env'] })

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