Availability:C-language interface function
bool PL_call(term_t 
t, module_t m)Call term t just like the Prolog predicate once/1. t 
is called in the module m, or in the context module if m 
== NULL. Returns TRUE if the call succeeds, FALSE 
otherwise. If the goal raises an exception the return value is
FALSE and the exception term is available using
PL_exception(0).230Up 
to version 9.1.11 the debugger was started and the exception was not 
propagated.
Figure 7 shows 
an example to obtain the number of defined atoms.