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What I also like about your version is that you do not have to "convert" the value for the texture map node, just change the sign.

I have just noticed that we do not have to change the sign when we use the Substract node (I tried with the Add node).
That`s good because now we can extract the Origin parameter of the Texture Map node and connect it to the Constant node (used to offset the area branch). This way we can define the position of both, the area AND the texture node, simply by entering the values we want into the Constant node entry field.

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