Indirect Resource
Also called Piān Yìn, the Partial Seal
A chart describes tendencies in a traditional system. It cannot decide health, money, law, marriage or children.
In the classical sources
倒食即偏印之谓，一名吞啖煞，食神最忌见之。
Upended Food is another name for Indirect Resource. It is also called the Swallowing Killer, and the Eating God most dreads meeting it.
三命通會 卷六
About this relation
Four names circulate for this one position: 偏印, 倒食, 梟神 and 吞啗煞, the swallowing killer, and 淵海子平 lists the first three together. The calculator prints 偏印, rendered Indirect Resource. Look for the element that feeds the day master and take its stem of matching polarity: water feeds wood, so yang 壬 is the Indirect Resource of yang 甲.
倒食, upended food, explains itself in the worked case of 三命通會 卷六. 甲 relies on 丙 as its Eating God, and 壬 overcomes 丙, so the chain from food to wealth to office stops. The alarming titles describe that one interruption, a job done on one stem by another.
Even inside 三命通會 the opinion of this pair varies, since 卷五 says 甲 likes to be produced by 壬 and dislikes being produced by 癸, the opposite of what the title 倒食 would lead you to expect. 淵海子平 for its part speaks flatly of thin fortune and short years for charts of this kind. That is an old manual's way of speaking, and it sits here as a report and not as a forecast for anyone's chart or life. Modern popular BaZi links the position with intuition and unusual learning, which none of these chapters say.
Where this text comes from
The quotation and the attributed statements follow the Wikisource texts listed here. The relation rule is the method used by the calculator.
The English name follows common modern usage. The wording here is our own plain summary.