# jumping of type in generalized complex structure

We know that the "type" of generalized complex structure may vary throughout the manifold, in fact the "type" can be thought of as the number of transverse complex directions, and so is an upper semi-continious function on the manifold. (each point has a neighbourhood in which it does not increase). Why, when the "type" is zero, are there only symplectic directions and when then "type" is $n$, all the directions are complex? and why does "type" jump up always by an even number?

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