var x : int = 4;
var y := 3.2;

assert x == 4;
assert x != 5;
assert y == 3.2;
assert y != 3.1;

var a := (b := (c := 4));
assert a == 4;
assert b == 4;
assert c == 4;

a = 9;
assert a == 9;

var u := 0;
var v := 0;

u = (v = 17);
assert u == 17;
assert v == 17;

# SCOPES
# ======

var a0 := 42;

{
  assert a0 == 42;
  var a0 := 3;
  assert a0 == 3;

  {
    var a0 := 777;
    assert a0 == 777;
  }

  {
    var a0 := 19;
    assert a0 == 19;
  }

  assert a0 == 3;
}

assert a0 == 42;