true if Frame
still is a candidate for backtracking; false otherwise.goal, but only returning the [<module>:]<name>/<arity>
term describing the term, not the actual arguments. It avoids creating
an illegal term as goal and is used by the library library(prolog_stack).true if Frame
is the top Prolog goal from a recursive call back from the foreign
language. false otherwise.true if the frame is
hidden from the user, either because a parent has the hide-childs
attribute (all system predicates), or the system has no trace-me
attribute.true if this frame was skipped in the
debugger.clause (the goal has
alternative clauses), foreign (non-deterministic foreign
predicate), jump (clause internal choice-point), top
(first dummy choice-point), catch (catch/3
to allow for undo),
debug (help the debugger), or none (has been
deleted).
This predicate is used for the graphical debugger to show the choice-point stack.
true if no choicepoint exists
that is more recent than the entry of the clause in which it appears.
There are few realistic situations for using this predicate. It is used
by the
prolog/0
toplevel to check whether Prolog should prompt the user for
alternatives. Similar results can be achieved in a more portable fashion
using call_cleanup/2.