A more thorough explanation:

The one-subject rule is a principle that states that a law should only cover one topic, and that topic should be clearly stated in the law's title. This rule helps to ensure that laws are clear and concise, and that lawmakers do not try to sneak unrelated provisions into a bill.

For example, a law that is titled "An Act to Increase Funding for Public Schools" should only contain provisions related to education funding. It should not include unrelated provisions, such as tax breaks for corporations or changes to environmental regulations.

Another example would be a law titled "An Act to Regulate the Sale of Tobacco Products." This law should only contain provisions related to the sale and distribution of tobacco products. It should not include provisions related to other products, such as alcohol or firearms.

These examples illustrate how the one-subject rule helps to ensure that laws are focused and clear. By limiting each law to one topic, lawmakers can avoid confusion and ensure that the public understands what the law is intended to do.