// arrays are created as literals, by simply listing elements, or by a generator expression, or a combination.
def a: [1, 2, 3..7:2, 11];
$a -> !OUT::write
'
' -> !OUT::write

// Natural indexes start at 1
$a(1) -> !OUT::write
'
' -> !OUT::write

// But you can have an array start at any index
def b: -5:['foo', 'bar', 'qux'];
$b(-3) -> !OUT::write
'
' -> !OUT::write

// You can select a range
$a(3..last) -> !OUT::write
'
' -> !OUT::write

// Or a permutation/selection
$a([4,1,5]) -> !OUT::write
'
' -> !OUT::write

// Values in Tailspin are generally immutable, but there is a mutable slot in a function/templates.
// A mutable array can be appended
5 -> \(@: [1,2]; $ -> ..|@: $; $@ ! \) -> !OUT::write