Overlapped range with integral

A=[ 0.2 2 2.5 3 2.4 2.9 ] is used to represent the range of Xmin and Xmax of integral

With the elements of array A, I can easily write the code:

integral(function,A(1),A(2)) + integral(function,A(3),A(4))+ integral(function,A(5),A(6))

But I don't want the overlapped range 2.5~2.9 between A(3)~A(6) that will make the result larger

How can I deal with this overlapped range ? Thanks a lot.