text: #include <stdio.h>
  #include "header.h"
  
  #define ERROR_FUNC error
  #include "err.h"
  #undef ERROR_FUNC
  #define ERROR_FUNC errorANOTHER
  #include "err.h"
  
  int main() {
      say_two();
      say_three();
      say_four();
  
  	ERROR_FUNC();
  	error();
  	errorANOTHER();
      return 0;
  }
  
  // The body for the definition (declared in the header). Notice this is declared
  // after using the forward declaration above.
  void say_two() {
      printf("2");
  }
  