Does there exist a piecewise linear continuous function f:R→R such that for any two-way infinite sequence an∈[0,1], n∈Z, there exists an x∈R with
K→∞limsupK#{k≤K:k∈N,fk(x)∈[n,n+1)}=an
for all n∈Z, where fk=f∘f∘⋯∘f stands for the k-fold iterate of f? real analysisalgebraDensityMiklos Schweitzercombinatorics