Answer:
Hence there are four types of arguments: conclusive a priori, defeasible a priori, defeasible a posteriori, and prima facie conclusive a posteriori.
The definition of valid is something effective, legally binding or able to withstand objection. An example of valid is a driver's license that hasn't expired. An example of valid is someone giving evidence that proves an argument.
Valid: an argument is valid if and only if it is necessary that if all of the premises are true, then the conclusion is true; if all the premises are true, then the conclusion must be true; it is impossible that all the premises are true and the conclusion is false. Invalid: an argument that is not valid.
