title: defining and updating coordinates with pascal
body: <p>this is PASCAL;</p>
  
  <p>I have numeorus rectangles which are defined by their top right and bottom left corner coordinates like (x1,y1,x2,y2). i have to shift these coordinates by variables a and b  (x1+a,y1+b,x2+a,y2+b).</p>
  
  <p>is there an easy way to define these constants and then shift them? I am doing this by one by and it takes a long time. pls dont tell me to use "some concept or command" give an example code if possible</p>