(defun sum-array (inArray)
	(if (= (mod (length inArray) 2) 0)
		(let*
			(
				(outArray (make-array (/ (length inArray) 2)))
			)

			(labels
				((add-array (&optional (i 0))
					(if (>= i (length outArray))
						outArray
						(progn
							(setf
								(aref outArray i)
								(+
									(aref inArray (* i 2))
									(aref inArray (+ (* i 2) 1))
								)
							)
							(add-array (+ i 1))
						)
					)
				))
				(add-array)
			)
		)
		nil
	)
)

(sum-array #(1 2 4 4 4 4))