% This picture represents the Poincaré disc model of the hyperbolic plane
% (C) Thiago Brevidelli
\begin{tikzpicture}
  % The disk
  \draw (0, 0) circle (1);

  % A strait line in the hyperbolic plane
  \begin{scope}
    \clip (0, 0) circle (1);
    \draw (1, 1) circle (1);
  \end{scope}

  % The intersection of the strait line with infinity
  \fill (0, 1) circle (1pt);
  \fill (1, 0) circle (1pt);
\end{tikzpicture}

