program main
  fn main() -> i32
    call std.io.eprint
      string "diagnostic"
    local let arg_count: i32
      call std.process.argc
    local let first_arg: string
      call std.process.arg
        int 0
    local let env_value: string
      call std.env.get
        string "GLAGOL_EXP_3_ENV"
    local let input: string
      call std.fs.read_text
        string "glagol-exp-3-input.txt"
    local let status: i32
      call std.fs.write_text
        string "glagol-exp-3-output.txt"
        var input
    binary +
      var arg_count
      binary +
        var status
        call std.string.len
          call std.string.concat
            var first_arg
            var env_value