How about an infinity symbol held within a square -to use the mathematical formula to calculate the area of a circle -or trapped within a cubic prison for a sphere.

I've always related four pointed forms to deception; which could gift the nature of the circle. Though, there is a duality within a circle and a oneness within a sphere.

Maybe also consider what is being removed for something other to take it's place. There is separation/splitting occurring as well.

You've got a complex equation to work out here.