Predicates compiled with YAP's flag call_counting set to on update counters on the numbers of calls and of retries Counters are actually decreasing counters, so that they can be used as timers Three counters are available:

• calls: number of predicate calls since execution started or since system was reset;
• retries: number of retries for predicates called since execution started or since counters were reset;
• calls_and_retries: count both on predicate calls and retries

These counters can be used to find out how many calls a certain goal takes to execute They can also be used as timers

The code for the call counters piggybacks on the profiling code Therefore, activating the call counters also activates the profiling counters

These are the predicates that access and manipulate the call counters