Assertion: ellipse's foci | /r/AtLocation | same point
Facets:
Source sentences:
text: In fact a Circle is an Ellipse, where both foci are at the same point (the center).
text: A circle is also an ellipse, where the foci are at the same point, which is the center of the circle.
text: the foci are at the same point so there is really only 1 focus