1560 — Eq. (17) and Eq. (18) Have Identical Endpoint Coefficients
Hard-to-vary claim
Once the integrated boundary Hamiltonian is typed as
the direct exponent in Eq. (17) and the Hamiltonian representation in Eq. (18) have identical quadratic coefficients:
Therefore the factor-two mismatch isolated in Entry 1558 is not introduced by replacing with an endpoint Hamiltonian insertion.
Exact comparison
Equation (17) gives
Equation (18) gives
and substituting produces the same expression. Entry 1559's separated regulator verifies that the local notation realizes this integrated identity without a diagonal excess.
Artifacts
research/benincasa/checkers/eq17_eq18_endpoint_expansion.rsresearch/benincasa/results/eq17-eq18-endpoint-expansion.json
Narrow conclusion
The source discrepancy is downstream of Eq. (18). Given the independently checked sector reductions
the first unresolved step is the unpublished contraction/reduction that produced Eq. (19)'s doubled boundary-containing coefficients.
This does not yet prove that Eq. (19) is wrong: an omitted contraction family could still supply a second copy of both boundary-containing sectors. But it cannot come from exponent combinatorics, endpoint delta mass, or a simple diagonal contact.
Next falsifier
Perform a labelled Wick census directly from the unsymmetrized slots for all connected two-point fish contractions. Partition it by bulk--bulk, mixed, and boundary--boundary location. Test whether any contraction family is absent from the compact sector formulas while leaving the bulk coefficient unchanged.