/in/foo.cc: In function 'int main()':
/in/foo.cc:7:26: error: 'i' was not declared in this scope
    7 |         for(int n=a;n<=b;i++)
      |                          ^
/in/foo.cc:13:30: warning: statement has no effect [-Wunused-value]
   13 |                         false;
      |                              ^