non-linear operation in GStreamer

["moayyad sadi" <alsadi at gmail dot com>]

I was having fun with GStreamer,

but I have a question about nonlin plugins

how to make use of them

let's assume we have three clips and the fourth is the reslut
each having the following time line

1: -[0 ----- 1 ----- 2]----- 3 ----- 4 ----- 5 ----- 6 ----- 7 ----- 8
       ie. first 3 min of it
2: - x ----- x ----- [1 ----- 2 ----- 3] ----- 5 ----- 6 ----- 7 -----
8      ie. first 3 min of it added after the previous one
3: - 2 ----- 3 ----- 4 ----- 5 ----- [6 ----- 7 ----- 8] ----- 7 -----
8     ie. add min from 6-8 of the last clip after the last one
4: -[0 ----- 1 ----- 2 ----- 3 ----- 4 ----- 5 ----- 6]----- 7 ----- 8
      ie. to give this long clip

so how can we use the gnloperation element
to combine the three clips into the fourth