Rule of inference

Imagine you are playing with some toys and you have a set of rules you need to follow to play properly. For example, if you want to build a tower, you need to start with the biggest block at the bottom and put smaller ones on top.

Similarly, in math and logic, we have some rules we need to follow to make sure our reasoning and arguments make sense. These rules are called rules of inference. They help us draw conclusions based on the information we have.

For example, let's say we know that "all dogs are mammals" and we also know that "my pet Max is a dog". Using the rule of inference called modus ponens, we can conclude that "Max is a mammal".

This rule of inference states that if we have a statement like "if A is true, then B is true" (in our example, "if Max is a dog, then Max is a mammal") and we also know that A is true (in our example, that "Max is a dog"), then we can infer that B is true (in our example, that "Max is a mammal").

There are many other rules of inference that help us draw conclusions based on the information we have. They might seem complicated, but just like following the rules of a toy game, they are there to help us play fair with our reasoning in math and logic.