Listing 4. The screen output of the F-PC program shown at the listing 3.
The array words are redefined to perform range checking.

ARRAY, isn't unique
[]LEN isn't unique 
[] isn't unique 
[]! isn't unique 
[]^ isn't unique 
   48 \ 1-dimensional array:  
   49 11 22 33 44   4 array,  constant y  
   50 -1 y [] .  
*** invalid index -1 for the array at 33595 
4 
   51 0 y [] .  11 
   52 1 y [] .  22 
   53 3 y [] .  44 
   54 4 y [] .  
*** invalid index 4 for the array at 33595 
-28695 
   55   
   56 \ 2-dimensional array  
   57 \ The last, delimiting, subarray is needed for []len  
   58 \ to calculate the length properly  
   59 \ NB: we use the same syntax but *different* versions of array words.  
   60 1  2  3  4  5   5 array,  
   61 6  7  8  9      4 array,  
   62 10 11 12        3 array,  
   63                 0 array,  
   64                           4 array, constant x  
X isn't unique 
   65 0 0 x [] [] .  1 
   66 -2 0 x [] [] .  
*** invalid index -2 for the array at 33610 
-31941 
   67 0 -2 x [] [] .  
*** invalid index -2 for the array at 33642 
8397 
   68 -1 -2 x [] [] .  
*** invalid index -2 for the array at 33642 

*** invalid index -1 for the array at 0 
8238 
   69 0 x []len .  5 
   70 -1 x []len .  
*** invalid index -1 for the array at 33642 
16802 
   71 3 x []len .  
*** []LEN does not work for the last ( 3 ) subarray (of array at 33642 )
28351 
   72 4 x []len .  
*** invalid index 4 for the array at 33642 
1226 
   73   
   74 off> listvar