// Example: I96c9e1
print "Example: I96c9e1";
previous_setting := GetEchoInput();
SetEchoInput(true);
factl := function(n)
    error if n lt 0,
        "Error in 'factl': Argument should be >= 0";
    if n lt 2 then
        return 1;
    end if;
    c := n - 1;    
    answer := n;         
    while c gt 1 do
        answer *:= c;
        c -:= 1; 
    end while; 
    return answer;
end function;
SetEchoInput(previous_setting);
