#lang racket

(define-syntax-rule (M <num-rows> × <num-columns> (<x-tag> <y-tag>) <f>)
  (λ args
    (define (element-at arg1 arg2)
      (match <f>
        [(,func ,params ...) (apply func (map element-at params))]
        [<x-tag> arg1]
        [<y-tag> arg2]
        [x x]))
    (match args
      [`(,arg1 ,arg2) (element arg1 arg2)]
      [`(rows) <num-rows>]
      [`(columns) <num-columns>]
      )))