c - The #define variable usage -

I am working on a project written in the C programming language. I found a code snippet below

  unsigned letters [10]; #define arr () (& amp; value [0])   
 How have they defined "function" ( arr () )  # Define the variable for an unsigned four array?  
 They are trying to use variables such as  arr () [1], arr () [2]  etc.  
 
  arr () + 2  is equal to  value + 2 . I tried to run a small program, but due to two results I got different answers. How is this possible. Because they are telling the address of the first array on  arr () . Should not these two be equal? Can anyone explain what is the significance of defining a variable as above?   
 
 
 I can not tell you  why  they did it, but yes,  arr () + 2  and  value + 2  are the same thing.