Full-slice qSDDOp averaging identity #
Averaging identities expanding the full-slice qSDDOp and proving the scalar commutation
identity fullSliceCommutation_qSDDOp_avg_eq: the counterpart of
MIPRE/Background/LIDT/MIPStarRE/LDT/Commutativity/Transport/FullSlice/Bridges/QSDD.lean in the
port of planning/c6b-plan.md (milestone M7, section "Port conventions"). This scalar expansion
is used by the full-slice transport theorems that compare the quartic scalar averages appearing
in commutativity-G.tex.
The vendored proof of the expansion works with the Kronecker placements leftTensor (ι₂ := ι) A
and proves their self-adjointness through Matrix.PosSemidef; here the commutator identity
(AB − BA)^*(AB − BA) = BAB + ABA − BABA − ABAB is proved in the local algebra 𝔓 and placed
once by strategy.state.L, as in EvaluatedSliceCommutation/Averages.lean.
Not ported #
Every declaration of the vendored file has a counterpart here.
References #
In LionSR/MIPStarRE at commit 507e8122, not in this repository:
references/ldt-paper/commutativity-G.texblueprint/src/chapter/ch08_commutativity.tex
Expand the averaged full-slice qSDDOp into the four projector terms
BAB + ABA - BABA - ABAB.
Paper eq:gcomterms (commutativity-G.tex lines 286-290).
Full-slice analog of evaluatedSliceCommutation_qSDDOp_avg_eq: the pulled-back sddErrorOp
on the full-slice product equals 2·(ABAAvg − ABABAvg) after using projectivity and the
(x,g) ↔ (y,h) symmetry to collapse BAB + ABA − BABA − ABAB into the two surviving scalar
quartic terms.