set the trace evisc tuple
Major Section:  TRACE

A trace evisc-tuple, which is set by this utility, provides a means to restrict printing during tracing. By default the ACL2 trace mechanism, trace$, automatically deals with stobjs, the logical world, and certain other large structures. See trace$, in particular the documentation of trace$ option :hide. However, even with that default behavior you may want to restrict what is printed according to the print-level and print-length of an evisc-tuple; see ld-evisc-tuple.


; Set trace evisc tuple to a standard value, using current Lisp *print-level* ; and *print-length* variables: (set-trace-evisc-tuple t)

; Set trace evisc tuple back to its default: (set-trace-evisc-tuple nil)

; Set trace evisc tuple to restrict print-level to 3 and print-length to 4, ; while hiding the logical world and suitably printing stobjs even if trace$ ; option ``:hide nil'' is used. (set-trace-evisc-tuple (evisc-tuple 3 4 (trace-evisceration-alist state) nil))

General Forms:

(set-trace-evisc-tuple nil) ; default trace evisc-tuple set to standard value (set-trace-evisc-tuple t) ; default trace evisc-tuple set to hide the ; logical world and deal with stobjs even when ; trace$ option ``:hide nil'' is supplied (set-trace-evisc-tuple evisc-tuple) ; default trace evisc-tuple set to evisc-tuple

See trace$ for a discussion of ACL2 tracing. The evisc-tuple (e.g., see ld-evisc-tuple) used by that trace utility is the one last installed by set-trace-evisc-tuple -- initially to the default of nil -- unless overriden by trace option :evisc-tuple.

Remark. If you use value t, then ACL2 will ensure that the logical world and stobjs are kept up-to-date in the trace evisc-tuple.