Definition: Cutoff declaration

A cutoff declaration specifies:

1. the geometric stopping mass $M_{\mathrm{cut}}$;

2. selected species, angular modes, frequencies, and packets;

3. occupation and numerical truncations;

4. the treatment of every discarded sector;

5. the input class and topology in which each truncation error is bounded.

A trace-preserving failure flag is distinguished from postselection.