钩深索隐

Explanation: Hook: hook to take; Cable: Explore. Take deep color, and explore hidden. So sophisticated that study to explore the hidden things. 　　Source: "Book of copulative on" An Exploration into the Solitude hook deep Zhi Yuan. " 　　Examples: Sighted to take the reading of the, ~, pains, not to cave candles and attainment. (Caidong Fan, Xu Jin Father "Popular Republic of Kingdoms" preface)