Which accounting assumption or principle is being violated if a company is a party to major litigation that it may lose and decides not to include the information in the financial statements because it may have a negative impact on the company's stock price?

The accounting assumption is the full disclosure. For a business, the full disclosure rule requires an organization to give the important data with the goal that individuals who are acclimated to perusing monetary data can settle on educated choices concerning the organization. 
A disclosure is an extra data connected to an element's money related proclamations, normally as a clarification for exercises which have fundamentally affected the substance's monetary outcomes.

The answer is fast food restaurants use technology designed to reduce the need for skilled labor.