Wrong Parser Error UnexpectedEndOfInput

[DrSloth]

fn combinations {
    let l = args[0]
    result = array()
    for x in range(0, sub(len(l), 1)) {
        let ls = slice(l, add(x, 1))
        for y in ls {
            result = push(result, array(l[x], y))
        }
    }

    ret result
}

const PI = 3.14159265358979323
const SOLAR_MASS = mul(4, PI, PI)
const DAYS_PER_YEAR = 365.24

gives error:
ERROR [l. 17]: The file/command ended unexpectedly. Are you missing something?

Adding println("HI") at the end resolves the errror