Real projective plane
= Real projective plane
{wiki}
The real projective plane is the quotient of $S^2$ by $x\sim-x$ and parametrizes lines through the origin in $\mathbb R^3$.
= Real projective plane
{wiki}
The real projective plane is the quotient of $S^2$ by $x\sim-x$ and parametrizes lines through the origin in $\mathbb R^3$.