Initialisation ,   ,  
Main procedure
(1) Generate a binary population B according to .
(2) Perform function evaluations and find the best
solution b from .
(3) Update using (5).
(4) Set to in cases that it is out of the interval.
(5) If the termination condition is met, stop the procedure;
otherwise, set and go to (1).
Algorithm 1: Population-based incremental learning.