The probability P(A) of an event A is a measure of the likelihood that the event will occur on any trial. For a fixed conditioning event C, this assignment to all events constitutes a new probability ...The probability P(A) of an event A is a measure of the likelihood that the event will occur on any trial. For a fixed conditioning event C, this assignment to all events constitutes a new probability measure which has all the properties of the original probability measure. In addition, because of the way it is derived from the original, the conditional probability measure has a number of special properties which are important in applications.
