*left gray areas={x∈S|⋂n=−11hn(S)∈S}{\displaystyle \mathrm {left\ gray\ areas} =\{x\in S|\bigcap _{n=-1}^{1}h^{n}(S)\in S\}}
center gray areas={x∈S|⋂n=−22hn(S)∈S}{\displaystyle \mathrm {center\ gray\ areas} =\{x\in S|\bigcap _{n=-2}^{2}h^{n}(S)\in S\}}
right gray areas={x∈S|⋂n=−33hn(S)∈S}{\displaystyle \mathrm {right\ gray\ areas} =\{x\in S|\bigcap _{n=-3}^{3}h^{n}(S)\in S\}}
where S is a square and h is Smale Horseshoe map.
Own work
Yapparina