Big news for those who have been considering the purchase of a new Rolex watch from an authorized retailer: Rolex has recently announced (and confirmed) that it will be offering a 5-year warranty to go with all watches sold, starting from July 1, 2015 from authorized dealers.
The a priori/a posteriori distinction is sometimes applied to things other than ways of knowing, for instance, to propositions and arguments. An a priori proposition is one that is knowable a priori and an a priori argument is one the premises of which are a priori propositions. Correspondingly, an a posteriori proposition is knowable a posteriori, while an a posteriori argument is one the premises of which are a posteriori propositions.
Although the use of a priori to distinguish knowledge such as that which we have in mathematics is comparatively recent, the interest of philosophers in that kind of knowledge is almost as old as philosophy itself.