I got your question, it is quite easy to understand the logic of this particular expression like let consider some elements 1,2,3,4,5 and 6 when you given that find the numbers less than 5 you will find 1,2,3 and 4 but here if we use logical not operator like "!" in this question it become-- find elements which are not less than 5 only 2 elements left i.e 5 and 6 so that concluded it is by default considered that a>b and a can be equal to b. Thanks you.