[eclipse-users] invoking module function from C API

Hi,

I have the following module installed in the lib directory of Eclipse:

:- module(calendric_unit).

:- lib(ic).
:- lib(calendar).

:- export
    interval/3,        % interval(julian_time, interval_type, result)

interval(X,month,Interval) :- mjd_to_date(X, D/M/Y), date_to_mjd(1/M/Y,Ini),
Tmp is M+1,date_to_mjd(1/Tmp/Y,End), Interval $>= Ini, Interval $<End.

I'm invoking "interval" from the C API. I want to execute the goal and to
obtain the value in Interval.

My code (in C++) is like this:

#include "eclipseclass.h"
#include <stdio.h>

int main(int argc, char** argv)
    {
        ec_init();

    EC_ref result;

    post_goal(term(EC_functor("import",1), EC_atom("calendric_unit")));
    post_goal(term(EC_functor("interval",3), EC_word(54000),
EC_atom("month"), result));

        if (EC_succeed == EC_resume()){
        printf("\nok");
    }else{
        printf("\nfail");
    }
        ec_cleanup();
    }

I can compile the program sucessfully, but when I execute it I get the
following error:

calling an undefined procedure interval(54000, month, _1075) in module
eclipse

Segmentation fault (core dumped)

I can sucessfully compile and execute simple examples, for example the
writeln ones that come in the documentation.

Could you help me?

Many thanks in advance,

Carlos