base/double-quad-to-qquad

Level

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

Fidelity

renderPreserves rendering under the reference renderer.

Package

base

Source

base/authoring/spacing_merge/double_quad_to_qquad.rs (opens in new tab)

Triggers

\quad command

Produces

\qquad command

Touches

\quad command

Rewrite patterns#

1. \quad\quad\qquad

Examples#

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

A\quad\quad B

A\qquad B

\text{A\quad\quad B}

\text{A\qquad B}

Related rules#

Upstream rules#

• base/double-enspace-to-quad Rewrite two adjacent enspaces to one exact-width quad.

Downstream rules#

• base/qquad-drop Drop qquad in math mode and collapse each text-mode qquad run to one ordinary space.

Same family#

• ams/nobreakspace-to-tilde Collapse nobreakspace to the canonical nonbreaking space token.
• base/break-to-linebreak Collapse break to the explicit linebreak command.
• base/newline-to-linebreak Collapse newline to the explicit linebreak command.
• base/control-space-to-tilde Rewrite math-mode control space to the canonical active space token.
• base/gt-space-to-colon-space Collapse \> to the canonical medium math space command \:
• base/hfil-to-hfill Collapse hfil to the canonical hfill command under MathJax spacing semantics.
• base/hfilll-to-hfill Collapse hfilll to the canonical hfill command.
• base/hskip-to-hspace Collapse hskip to the explicit hspace command.
• base/negthinspace-to-neg-comma-space Collapse negthinspace to the explicit negative thin math space command.
• base/space-to-tilde Collapse space to the explicit nonbreaking space token.
• base/thinspace-to-comma-space Collapse thinspace to the explicit thin math space command.
• base/double-enspace-to-quad Rewrite two adjacent enspaces to one exact-width quad.
• base/small-spacer-merge-to-enspace Merge exact half-em small-spacer chunks into enspace in one pass.
• base/allowbreak-drop Drop allowbreak as a pure linebreak hint during cleanup-oriented normalization.
• base/badbreak-drop Drop badbreak as a pure linebreak hint during cleanup-oriented normalization.
• base/goodbreak-drop Drop goodbreak as a pure linebreak hint during cleanup-oriented normalization.
• base/mathstrut-drop Drop the invisible mathstrut layout helper in cleanup-oriented normalization.
• base/nobreak-drop Drop nobreak as a pure linebreak hint during cleanup-oriented normalization.
• base/strut-drop Drop the fixed empty strut node in cleanup-oriented normalization.
• base/enspace-drop Drop enspace in math mode and collapse each text-mode enspace run to one ordinary space.
• base/qquad-drop Drop qquad in math mode and collapse each text-mode qquad run to one ordinary space.
• base/quad-drop Drop quad in math mode and collapse each text-mode quad run to one ordinary space.
• base/mkern-to-mspace Collapse mkern to the explicit mspace command.
• base/mskip-to-mspace Collapse mskip to the explicit mspace command.

Notes#

Both commands are MathJax Spacer nodes at scriptlevel 0, so two 1 em quads exactly equal one 2 em qquad. This Authoring-level canonicalization scans from left to right and replaces every two adjacent quads; one trailing quad remains for odd-length runs. The base owner also matches the same-name textmacros record by command name, covered by the text-mode example. The Equiv spacing-drop family eliminates both quad and qquad, so enabling or omitting this canonicalization does not change the final Equiv normal form. Every Applied result consumes two adjacent cmd:quad nodes and produces no cmd:quad, so the total cmd:quad count strictly decreases.

Disable this rule#

TransformEngine(profile="corpus", disable_rules=["base/double-quad-to-qquad"])

new TransformEngine({ profile: 'corpus', disableRules: ['base/double-quad-to-qquad'] })

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