## Spectrum of C_heart where

1 + z + 2\sqrt{1 - z^2}
heart(z)= -------------------------
3 - z + 2\sqrt{1 - z^2}

Figure 7.1, page 303, of "Composition Operators on Spaces of Analytic Functions"
Reprinted with permission from

"Composition Operators on Spaces of Analytic Functions"

by Carl C. Cowen and Barbara D. MacCluer.

Copyright CRC Press, Boca Raton, Florida.