premise: The Pulitzer Prize for Photography was one of the American Pulitzer Prizes annually awarded for journalism. It was inaugurated in 1942 and replaced by two photojournalism prizes in 1968: the Pulitzer Prize for Feature Photography and "Pulitzer Prize for Spot News Photography". The latter was renamed for Pulitzer Prize for Breaking News Photography in 2000.
hypothesis: The Pulitzer Prize for Photography is one of 20 different Pulitzer prizes.
reason: According to the above, we do not know how many Pulitzer prizes there are in total. The system must have some quantitative measurement that disagrees with this.