Mathematical logic can be used to make money in several ways. Here are some examples:

1. Cryptography: Cryptography involves encoding and decoding messages in a secure way. Mathematical logic is used to develop encryption algorithms that make it difficult for unauthorized individuals to access sensitive information. Cryptography is used by businesses to protect their financial information, customer data, and other confidential information.

2. Artificial Intelligence: Artificial Intelligence (AI) is an area of computer science that uses mathematical logic to develop algorithms that can perform human-like tasks such as speech recognition, image processing, and decision-making. Companies that use AI to improve their products or services can gain a competitive advantage and increase revenue.

3. Game theory: Game theory is a branch of mathematics that deals with strategic decision-making. It can be used in business to model competition and cooperation between companies, determine optimal pricing strategies, and develop marketing campaigns.

4. Financial modeling: Mathematical logic is used in financial modeling to create models that can be used to predict stock prices, interest rates, and other financial indicators. Financial institutions use these models to make informed investment decisions and minimize risk.

5. Optimization: Optimization is the process of finding the best solution to a problem within a set of constraints. Mathematical logic is used to develop optimization algorithms that can be used to optimize production processes, supply chain management, and other business operations.

These are just a few examples of how mathematical logic can be used to earn money. The key is to identify the specific application and use the appropriate mathematical tools to solve the problem at hand.