#lang racket/gui

;;; comment this line to make error go away
(require frtime)

(require "model.rkt")

(define simple-economy
  (model make-immutable-hash hash-ref
   ((? years #f)
    (? income (hash))
    (? expenses (hash))
    
    (= profit                   
       (for/hash ((y years))
		 (values
		  y
		  (- (hash-ref income y 0)
		     (hash-ref expenses y 0) ))))  )))