In Galapagos, the way to adjust variables is with the component called Gene Pool. The Gene Pool works similar to a number slider except that Galapagos will have control over these sliders. Double clicking the component to adjust the settings. Set the gene count to six, the decimal place to zero. Set the minimum value to zero because the opening is located at the edge of the roof. The maximum is the maximum distance that the opening should move to reach the other side of the roof. That value is the width of the roof minus the width of the panel which in our case is 1600.  

To see how the Gene Pool works, plug into the Unit Y component and as you move the sliders see how the panels move as well. We can check our math by moving it to the end and confirm that the panel doesn't overlap the end of the roof. Disconnect the Gene Pool by control clicking on the wire and dragging it back to the Gene Pool component. We have an intermediate step to complete first.  

To separate the outputs from the Gene Pool so they can be connected to different components, place the list item component. Connect the Gene Pool to the list input. All we see as an output is one single item but if we zoom very far into this component we see these plus buttons. Click the plus until we see ‘plus five’. This is because the gene pool outputs six values so each value will be sent to a different output. The first value is output at I, the second value to plus one then plus two and so on. This way we can choose separate components to plug each of these into.  

Also remember that the width of the roof is twice the length of our roof. We selected this simple ration because we can use only one gene pool slider to control the location of the panels. With Galapagos, you cannot set some sliders to output a number between a certain range and others to output a number between a different range. Because we know the length to width ratio, what we can do is use a division component. When placing it if we enter divide two and click enter, it will automatically set our B variable to 2 already.  

After dividing the value of the sliders by 2, connect the result into the X component to control the movement in the X direction. Shift click to connect I, plus one, and plus two to input A of the division component and plug the result into the Unit X vector. You can now see when moving the first three sliders, the panel moves in the X direction and doesn't go over the edge of the roof.  

I'm going to move these components to make them easier to see. Shift click and connect the plus three, plus four, and plus five, outputs to the unit Y component. That completes connecting all the inputs, which now allows us to move a component in the X direction and in the Y direction. Because we are still previewing all the sliders, it makes continuous copies of everything. So we can turn off the preview for the components up until this point. Then only our final opening locations will be visible.