Mouse stealing oil
Mouse stealing oil is a direct translation of the Chinese go term 老鼠偷油. It refers to the killing tesuji of , which exploits the fact that the four-stone Black chain has no outside liberties. This killing technique is a common theme in some life-and-death problems.
If prevents White from connecting, then cuts. Black is dead from double shortage of liberties.
here allows to connect back. Notice that in the presence of , the stone becomes an instance of the eye-stealing tesuji, and as such Black has no eye at a.
There appears to be no established English Go term for "mouse stealing oil", although the corresponding Chinese term 老鼠偷油 is commonly used. The direct translation "mouse stealing oil" appears in Guo Juan's The World of Chinese Go, and probably other places as well.