x_{1} (set of tuples) is the x_{4}-Winsorized data formed from data set x_{2} (set of tuples), Winsorizing with respect to variable x_{3}.

x_{4} (li; between 0 inclusive and 1 inclusive) is the threshold; any and only x_{3} values which are more extreme than what x_{4} allows will be replaced. In other words, any x_{3} value in/as an entry of a tuple in x_{2} which is less than the ((1-x_{4)/2)}th-quantile value of x_{3} in/from set x_{2} is replaced by the ((1-x_{4)/2)}th-quantile value of x_{3} in/from set x_{2}; any x_{3} value in/as an entry of a tuple in x_{2} which is greater than the (1-((1-x_{4)/2))}th-quantile value of x_{3} in/from set x_{2} is reppaced by the (1-((1-x_{4)/2))}th-quantile value of x_{3} in/from set x_{2}; all other values of x_{3} in/as an entry of a tuple in x_{2} remain unchanged; the newly generated set of tuples is x_{1}.