(located) at; (to be) in; to exist; in the middle of doing sth; (indicating an action in progress)[cedict]
钻牛角尖
zuān niú jiǎo jiānㄗㄨㄢ ㄋㄧㄡˊ ㄐㄧㄠˇ ㄐㄧㄢ
lit. to hone a bull's horn (成语 saw); fig. to waste time on an insoluble or insignificant problem; to bash one's head against a brick wall; a wild goose chase; a blind alley; to split hairs[cedict]