c events can be anything like: Probability basics It is raining, I miss the train, Mom calls, The check is in the mail, The flight has been delayed, The light bulb is burnt out, The client signed the contract, The team won the game. Here, the events are defined in the present or past tense, meaning that they are known facts. These known facts represent something that is either true or false, experienced or not, verified or not. If I say, "Tomorrow will be training," this is only an assumption concerning the future, which may or may not turn out to be true (for that matter, weather forecasts do not enjoy universal trust). Then tomorrow will tell, with rain being a more likely possibility among other ones. Thus, future events, as we may expect them to come out, are well defined facts associated with some degree of likelihood. If we are amidst the Sahara desert or in Paris on a day in November, then rain as an event is associated with a very low or a very high likelihood, respectively. Yet, that day precisely it may rain in the desert or it may shine in Paris, against all preconceived certainties. To make things even more complex (and for that matter, to make life exciting), a few other events may occur, which weren't included in any of our predictions. Within a given environment of causes and effects, one can make a list of all possible events. The set of events is referred to as an event space (also called sample space). The event space includes anything that can possibly happen. 1 In the case of a sports match between opposing two teams, A and B, for instance, the basic event space is the four-element set: team A wins team A loses (1.1) a draw game canceled with it being implicit that if team A wins, then team B loses, and the reverse. We can then say that the events "team A wins" and "team B loses" are strictly equivalent, and need not be listed twice in the event space. People may take bets as to which team is likely to win (not without some local or affective bias). There may be a draw, or the game may be canc