0> sub nd($$) { shift and shift; }
3> nd 2, 1
$res[1] = 1
4> nd nd 2, 2, 1
Too many arguments for main::nd at reply input line 2, at EOF
Not enough arguments for main::nd at reply input line 2, at EOF
5> nd (nd 2, 2), 1
Not enough arguments for main::nd at reply input line 1, near "2)"