If we want a machine to be intelligent enough to have a dialogue with us in natural language or do complex tasks like diagnosing a medical condition, or any problem-solving and decision making, then first the machine needs to become knowledgeable about the real word. Machine learning enables a machine to grow knowledgeable through automatic and experience-based learning without being explicitly programmed.
But the ability of automatic learning is feasible only if the machine can rightly interpret the information of our real world. However, a machine can’t understand our language, so the knowledge of the real world needs to be represented to the machine in the right manner that is readable to a computer system. Propositional logic is one of the simplest methods of knowledge representation to a machine.