 In the previous subsection we discussed a first principle of probability preservation, which says that if all premises have probability 1, then the conclusion also has probability 1. Of course, more interesting cases arise when the premises are less than absolutely certain. Consider the valid argument with premises \(p\vee q\) and \(p\to q\), and conclusion \(q\) (the symbol ‘\(\to\)’ denotes the truth-conditional material conditional). One can easily show that 