Real root isolation for exp-log-arctan functions

We present a real root isolation procedure for univariate functions obtained by composition and rational operations from exp,log,arctan and real constants. The procedure was first introduced for exp-log functions in Strzeboński (2008). Here we extend the procedure to exp-log-arctan functions, describe computation with elementary constants in detail and discuss the complexity of the root isolation procedure for the general exp-log-arctan case as well as for the special case of sparse polynomials. We discuss implementation of the procedure and present empirical results.