cascade corner pooling

[gr33n1]

Hey,
I am trying to understand this sentence from section 3.3 :

It first looks along a boundary to find a boundary maximum value

in other words "normal corner pooling"

then looks inside along the location of the boundary maximum value to find an internal maximum value

according to the drawing 4(b)/4(c) it looks like to find the internal max value it takes the maximum value from column of the maximum value found in the row of the top left corner. is it like that ???

And one more clarification - it is not necessarily in the center region ?

Thank you