Multiple cells compositions with a system of conditions (hard title)

Hey, same problem second try,
i am trying to make a system of conditions which will according to the condition will give a different volume.
For example, i have this rectangle:


and i would like to make a condition which by the width (by number of modules) will create a void in the middle:

in the same sense, i would like to make conditions which will make me other possibilities of form, for example:

or:

i am still learning the magic of GH, so there is a big chance i am missing something very basic.
will be grateful for any help and direction,

Form.gh (13.1 KB)