1. 1
2. 2
3. 3
4. 4
5. 5

def a :=
["def a :=", "#eval IO.println <| a.head (by decide)\n#eval a\n#eval IO.println <| a.tail.head (by decide)"]
#eval IO.println <| a.head (by decide)
#eval a
#eval IO.println <| a.tail.head (by decide)