mutable type abst ;
immutable type immut ;

char **globstring;

only abst abst_create (dependent abst p, only char *x, int i) 
   char **globstring; { }

only char *abst_name (abst a) { }
int abst_val (abst a) { }
int *abst_aval (abst a) { }
only abst abst_parent (only abst a) { }
dependent char *immut_name (immut im) { }
void abst_setIm (abst a, immut im) { }
immut abst_getIm (abst a) { }