physics/expectation-expand

Level

AuthoringFaithfulCorpusEquivFaithful, Corpus, and Equiv apply this rule.

Fidelity

renderPreserves rendering under the reference renderer.

Package

physics

Source

physics/faithful/bra_ket/expectation_expand.rs (opens in new tab)

Triggers

\ev command

Eliminates

\ev command

Produces

\left, \middle, \right commands

Rewrite patterns#

1. expectation-body-auto-sized\ev{#1}\left\langle #1 \right\rangle
2. expectation-body-fixed-size\ev*{#1}\langle #1 \rangle
3. expectation-state-auto-sized\ev{#1}{#2}\left\langle #2 \right\vert #1 \left\vert #2 \right\rangle
4. expectation-state-fixed-size\ev*{#1}{#2}\langle #2 \vert #1 \vert #2 \rangle
5. expectation-state-middle-sized\ev**{#1}{#2}\left\langle #2 \middle\vert #1 \middle\vert #2 \right\rangle

Examples#

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

\ev{H}_{\psi}=E_0

\left\langle H \right\rangle_{\psi}=E_0

\ev{H}{\psi}=E_0

\left\langle \psi \right\vert H \left\vert \psi \right\rangle=E_0

\ev*{A(t)}

\langle A(t) \rangle

\ev*{H}{\psi}

\langle \psi \vert H \vert \psi \rangle

\ev**{H}{\psi}

\left\langle \psi \middle\vert H \middle\vert \psi \right\rangle

Related rules#

Same family#

• physics/matrixel-expand Expand matrix elements to explicit angle-bracket and bar fences.
• physics/physics-bra-expand Expand bra to an explicit angle-bracket and bar fence form.
• physics/physics-braket-expand Expand braket to an explicit angle-bracket form with a middle bar.
• physics/physics-ket-expand Expand ket to an explicit bar and angle-bracket fence form.
• physics/commutator-expand Expand commutators to explicit square-bracket fences.
• physics/poisson-bracket-expand Expand poisson brackets to explicit brace fences.

Notes#

Covers body-only and braced-state branches. The second star only changes the braced-state branch; body-only double-star input renders like the single-star body branch.

Disable this rule#

TransformEngine(profile="corpus", disable_rules=["physics/expectation-expand"])

new TransformEngine({ profile: 'corpus', disableRules: ['physics/expectation-expand'] })

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