base/buildrel-to-stackrel

Level

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

Fidelity

renderPreserves rendering under the reference renderer.

Package

base

Source

base/authoring/stacked_operator/buildrel_to_stackrel.rs (opens in new tab)

Triggers

\buildrel command

Eliminates

\buildrel command

Produces

\stackrel command

Rewrite patterns#

1. operator\buildrel #1 \over #2\stackrel{#1}{#2}
2. operator-external-scripts\buildrel #1 \over #2_{#3}^{#4}\stackrel{#1}{#2}_{#3}^{#4}

Examples#

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

A_n \buildrel n\to\infty \over = B_n

A_n \stackrel{n\to\infty}{=} B_n

X \buildrel \phi \over \longrightarrow Y

X \stackrel{\phi}{\longrightarrow} Y

Related rules#

Downstream rules#

• base/stackrel-expand Expand stackrel to an explicit relation-level stacked operator form.

Same family#

• ams/substack-expand Expand substack directly to the explicit centered subarray environment.
• base/duplicate-mathrel-wrapper-drop Drop one directly nested duplicate mathrel wrapper.
• base/widehat-to-hat Drop stretchiness from \widehat by rewriting it to \hat.
• base/widetilde-to-tilde Drop stretchiness from \widetilde by rewriting it to \tilde.
• base/stackbin-expand Expand stackbin to an explicit binary-level stacked operator form.
• base/stackrel-expand Expand stackrel to an explicit relation-level stacked operator form.

Notes#

buildrel has argspec u{\over} m: the annotation is read up to a level-0 \over and the operator is the following mandatory argument, so \over is ArgumentKind::Until delimiter metadata rather than a sibling infix node and touches is empty. As for a TeX delimited parameter, an annotation that is exactly one braced group loses that brace layer at parse time; a \over inside braces is not a terminator. Scripts after the operator argument stay attached to the whole stackrel, while scripts inside a braced operator stay inside it. stackrel is the accepted Authoring form; Faithful expands it further through stackrel-expand. Like other unbraced mandatory arguments, an unbraced compound operator such as \frac{a}{b} is accepted as one argument even though TeX would reject it.

Disable this rule#

TransformEngine(profile="corpus", disable_rules=["base/buildrel-to-stackrel"])

new TransformEngine({ profile: 'corpus', disableRules: ['base/buildrel-to-stackrel'] })

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