Bridge 3: measurements and the zero-cost obstruction

Even away from a proposed critical point, $p>0$ does not restore the exact law required by 212-02. A coupling gives ${\tilde{w}}_e\le w_e$, hence $\tilde{T}\le T$, but this one-sided comparison does not transfer strict convexity or differentiability by Proposition prop:nonstable.

The complete monitored instrument is well defined and retains all outcomes. Its conditional entanglement is not the entropy of the unconditional mixed output. Neither a measurement threshold nor critical exponents are proved here. Family 213 is not an input to these assertions.