Not sure this answers exactly to the specs, but it does avoid the duplication: (define get-pos (lambda (pos a-grid-plane a-cell) (match-define (cell row-pos col-pos) a-cell) (define cell-size (grid-plane->cell-size a-grid-plane)) (match-define (size cell-w cell-h) cell-size) (case pos [(top-right-x) (+ cell-w (* col-pos cell-w))] [(top-right-y) (* row-pos cell-w)] ....))) Laurent <div class="gmail_quote">On Mon, May 7, 2012 at 11:41 PM, Patrick Mahoney <<a href="mailto:paddy.mahoney@gmail.com" target="_blank">paddy.mahoney@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div id=":3q">(define top-right-x (lambda (a-grid-plane a-cell) ;;The next three definitions are what I am looking to abstract over, as they show up in many similarly defined functions.|# (match-define (cell row-pos col-pos) a-cell) (define cell-size (grid-plane->cell-size a-grid-plane)) (match-define (size cell-w cell-h) cell-size) (+ cell-w (* col-pos cell-w)))) (define top-right-y (lambda (a-grid-plane a-cell) (match-define (cell row-pos col-pos) a-cell) (define cell-size (grid-plane->cell-size a-grid-plane)) (match-define (size cell-w cell-h) cell-size) (* row-pos cell-w))) </div></blockquote></div>