标准的倒锤头，倒锤头下方无影线：

倒锤头:H-L>3*(MAX(O,C)-LOW) AND MIN(O,C)=L ;

T形:O=H AND H=C AND L<C;
倒T字:O=L AND L=C AND H>C;
光头小阳:C=H AND L<O;
光脚小阳:L=O AND H>C AND C>O;
光头光脚阳线:O=L AND C=H;
十字星:O=C AND H>C AND L<C;