Where is Expression F1 (One variable function)

Hi, I am new in the Grasshopper environment and following some tutorials. Since I have the latest version of Rhino6/Grasshopper I cannot find some components when I refer to tutorials I am watching.

So where can I find the one variable function? I only have F2 with x and y. But I need only x. Can you help me?

Zoom the canvas you will see a minus near Y, click on minus.

that was so easy =) thanks