let a = 4
let b = 7
let c = a * b + 1

assert 29 == c

let d = [[2, 4], [6, 8]]
assert 6 == d[1, 0]
assert [2, 4] == d[0]
assert [6, 8] == d[1]

let e = 0
let f = 1
assert [2, 4] == d[e]
assert [6, 8] == d[f]

let! g = 4