text: #ifndef REGISTER_H
  #define REGISTER_H
  extern void invalidInst(void);
  extern int dec(char ch);
  extern void Stype(char* inst, int i);
  extern void Rtype(char *inst, int i);
  extern void Itype(char *inst, int i);
  extern void ItypeL(char *inst, int i);
  extern int Btype(char *inst, int i);
  extern int Utype(char *inst, int i);
  # endif
  