struct symrec
{
  char *name;  /* name of symbol                     */
  int type;    /* type of symbol: VAR, FUN1, FUN2    */
  union {
    double var;           /* value of a VAR          */
    double (*funPtr)();  /* value of a FUN1, FUN2    */
  } value;
  struct symrec *next;    /* link field              */
};

typedef struct symrec symrec;
#define LENGTH 50

extern symrec *sym_table;
void init_table ();
symrec *putsym (char *, int);
symrec *getsym (char *);
int yylex();