Hi suresh,
As you already referred to sap help on this, and in mentioned example;
with key figure and detailed lock another user will not be able to work on the selection related to characteristics A, here system tries to lock all the values (multiple single values) of characteristics A, whereas in case of live cache lock another user will be allowed to work on this selection as system tries to lock intervals.
more precisely with above example user X is working on 01 and user Y want to work on a interval 2 - 4 so livecache lock which works on interval will allow user Y to work as desired selection is out of selection on which user X is working, where as in case of detailed lock system tries to lock all the values of characteristics A, which include 01 - 04 all values hence will not allow user Y to work.
Hope will help you
Rgds
Sourabh