这个公式有啥问题，为什么同样的条件有的运算正确，有的不对

=IF(AND(M4="",L4>$G$2),0,IF(AND(M4="",L4<$I$2),$G$2-$I$2+1,IF(AND(M4="",L4>=$I$2),$G$2-L4+1,IF(AND(M4<>"",M4>$G$2,L4>$I$2),$G$2-L4+1,IF(AND(M4<>"",M4>$G$2,L4<=$I$2),$G$2-$I$2+1,IF(AND(M4<>"",M4<=$G$2,L4>$I$2),M4-L4+1,IF(AND(M4<>"",M4<=$G$2,L4<=$I$2),M4-$I$2+1)))))))