Assertion: icosahedron | /r/HasProperty | close to sphere
Facets:
Source sentences:
text: \begin{pmatrix}x/\sqrt{x^2+y^2+z^2}\cr y/\sqrt{x^2+y^2+z^2}\\z/\sqrt{x^2+y^2+z^2}\end{pmatrix}$$ would be good enough (esp. as the icosahedron is already close to a sphere.