    data/codegroup-19981025/codegroup.c:42: fo ==> of, for
    data/codegroup-19981025/codegroup.c:44: fo ==> of, for
    data/codegroup-19981025/codegroup.c:151: fo ==> of, for
    data/codegroup-19981025/codegroup.c:576: fo ==> of, for
    data/codegroup-19981025/codegroup.c:578: fo ==> of, for
    data/codegroup-19981025/codegroup.c:590: fo ==> of, for
    data/codegroup-19981025/codegroup.c:653: fo ==> of, for
    data/codegroup-19981025/codegroup.c:671: fo ==> of, for