Nimrod array setup prolem

import streams
type
  TGridRow = array[1..6000, uint8]
  TGridSquare = array[1..6000, TGridRow]

proc test(a:uint16, gs:TGridSquare):seq[uint16] =
  echo($a)
  result = @[]
  result.add(a)
  result.add(12)
  return

var fs = newFileStream("e135s35",fmRead)
let numRow = readInt16(fs)
let numCol = readInt16(fs)
echo($numRow)
echo($numCol)
gs : TGridSquare

# I will be loading the array after processing the file
# but just want to test the parameter passing syntax

let ans:seq[uint16] = test(69,gs)

echo(ans.len)
echo(ans[1])