Solution to Duplicate define

Header_files/app1.i

@@ -0,0 +1,27 @@
+# 0 "app.c"
+# 0 "<built-in>"
+# 0 "<command-line>"
+# 1 "/usr/include/stdc-predef.h" 1 3 4
+# 0 "<command-line>" 2
+# 1 "app.c"
+# 19 "app.c"
+# 1 "A.h" 1
+# 22 "A.h"
+int sum(int a,int b)
+# 20 "app.c" 2
+# 1 "B.h" 1
+# 23 "B.h"
+int multiply(int a,int b)
+# 21 "app.c" 2
+
+
+int foo(int b);
+int foo(int b){
+
+}
+
+int main(){
+    int a = (15*15);
+
+    return 0;
+}