Function: _def_debug
Class: default
Section: default
C-Name: sd_debug
Prototype:
Help:
Doc: debugging level. If it is nonzero, some extra messages may be printed,
 according to what is going on (see~\b{g}). To turn on and off diagnostics
 attached to a specific feature (such as the LLL algorithm), use
 \tet{setdebug}.

 The default value is \kbd{0} (no debugging messages).
