/in/foo.cc: In function 'int main()':
/in/foo.cc:9:9: warning: the address of 'double j1(double)' will never be NULL [-Waddress]
 while(j1!=0)
       ~~^~~
/in/foo.cc:14:7: error: 'j2' was not declared in this scope
 while(j2!=0)
       ^~