time(:Goal)Execute Goal just like call/1
and print time used, number of logical inferences and the average number
of lips (logical inferences per second). Note that SWI-Prolog
counts the actual executed number of inferences rather than the number
of passes through the call and redo ports of the theoretical 4-port
model. If Goal is non-deterministic, print statistics for
each solution, where the reported values are relative to the previous
answer.