func f(a) {      # argument is local to the function
  var b = 100;   # local to the function
  c = 100;       # local to the function; does not overwrite outer c
  return a + 1;
}
var a = 10;      # local at top level
var b = 20;      # local at top level
c = 30;          # local at top level; there is no more-outer-scope c
if (NR == 3) {
  var a = 40;    # scoped to the if-statement; doesn't overwrite outer a
  b = 50;        # not scoped to the if-statement; overwrites outer b
  c = 60;        # not scoped to the if-statement; overwrites outer c
  d = 70;        # there is no outer d so a local d is created here

  $inner_a = a;
  $inner_b = b;
  $inner_c = c;
  $inner_d = d;
}
$outer_a = a;
$outer_b = b;
$outer_c = c;
$outer_d = d;    # there is no outer d defined so no assignment happens