In logic, a proposition has only two possible states: true or false. If a proposition is consistent with the facts, then it is a true proposition; If a proposition is inconsistent with the facts, then it is a false proposition. For example, "the sun rises in the east" is a true proposition, because it is an objective fact. And "all birds can fly" is a false proposition, because although most birds can fly, some birds can't, such as ostriches.
In mathematics, false propositions can also refer to untenable mathematical statements or theorems. For example, "1+ 1=3" is a false proposition, because in the basic mathematical definition, 1+ 1=2 is a true proposition.