Round 2 verification audit for C075

Model: gpt-5

Claim: As long as the two pi/2 parity-analysis pulses have phases offset by pi/2, the sum of the two parity measurements equals + independent of the absolute pulse phase.

Source alignment: source/supp_content.tex:144-144 (Supp. Mat. S5)

Prior official verdict: verified with failure_reason None.

Executable evidence: sympy_check.py. Sandbox rerun logs: sympy_check.log.

Independent audit: I scanned the copied script for imports/shared helper dependencies and reran it through the sandbox. The code is self-contained in this attempt directory and targets the claim strategy: Show that summing the parity for two analysis pulses offset by pi/2 cancels the phase dependence and yields +.. I checked the relevant family model rather than relying only on exit status; the rerun is treated as one reproducibility input.

Decision: Round 2 verdict is verified with failure_reason None and limitations []. Notes: Summed parity of two pi/2 pulses offset by pi/2 equals XX+YY exactly, independent of absolute phase phi (verified symbolically for generic phi; cross terms cancel). Matches paper.