get procedure?

[Paul Emsley]

I don't understand what xxx is.  Can you help? (Bit of a noob question, 
I feel).

  SCM rest = SCM_EOL;
  SCM arg_list = SCM_EOL;
  arg_list = scm_cons(SCM_MAKINUM(4), arg_list);
  arg_list = scm_cons(SCM_MAKINUM(1), arg_list);

  SCM func = xxx("-");

  SCM v = scm_apply_1(func, arg_list, rest);
  // Now v should be a scheme int 3
 

Thanks,

Paul.