typedef struct automrec {
          int d;              /*** Size of the alphabet ( 0 ... d-1 )  ***/
          int st;             /*** Number of states ( 0 ... st-1 )     ***/
          short **nextst;     /*** Transition function: nextst[st][ch] ***/
          short int *final;   /*** State i is final if final[i] != 0   ***/
          } *automata;

     automata stringautom( );
     automata starautom( );
     automata unionautom( );
     automata concatautom( );