= Gauge-condition independence of BRST-closed correlation functions
{title2=$\partial_t\langle\mathcal O\rangle=i\langle\mathcal O\,s\dot\Psi_t\rangle_c=0$}
For an admissible family of <gauge-fixing fermions>, variation inserts a <BRST-exact operator> into normalized correlations. If the measured operators are <BRST-closed>, the <graded BRST Ward identity> makes that insertion vanish. This extends gauge-parameter independence to changes of the gauge functional itself, provided the action and measure preserve <BRST symmetry> and the change produces no boundary contribution. It is the perturbative statement; global gauge-orbit problems require additional analysis.
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