begin   
comment exception sqrterr ;
	real r, s;
	
	xcplimit(sqrterr) := 3;
	xcpmark(sqrterr) := true;
	xcpmsg(sqrterr) := "sqrt exception";
	xcpaction(sqrterr) := 1; 

	r := -1;  
	s := sqrt(r);	
	write(s);
end.