Any Machine Learning algorithm to know a yes/no answer? Any Machine Learning algorithm to know the meaning of sentences? Specifically, I have sentences like, "we do not allow managers to trade derivatives", "We do not have policy on hedging", "our policy do not permit trading on stock", "trading is not allowed"... The actual sentence is longer. Any algorithm I can know whether trading on stock is allowed or not by programming? Thank you for your help!!!
I sounds like your need to consider Language Understanding services instead. There are a couple of providers of this type of service. The one I have used before is called LUIS from Microsoft:

https://www.luis.ai/home/index

It is not the algorithm you are looking for per se, but to solve your problem by implementing an algorithm, you need to develop a language understanding system using models based on deep learning neural nets, which is not a trivial exercise.