typedef struct automrec {
          short d;         /*** size of the alphabet ( 0, ..., d-1 )  ***/
          short st;        /*** number of states ( 0, ..., st-1 )     ***/
          short **nextst;  /*** transition function: nextst[st][ch] ***/
          short *final;    /*** state i is final if final[i] != 0   ***/
          } *automata;

     automata stringautom( str ) char *str;
     automata starautom( aut ) automata aut;
     automata unionautom( aut1, aut2 ) automata aut1, aut2;
     automata concatautom( aut1, aut2 ) automata aut1, aut2;