Inverse problems for ZS-operators and their isomorphisms

Consider two inverse problems for ZS-operators problems on the unit interval. It means that there are two corresponding mappings $F,f$ from a Hilbert space of potentials $H$ into their spectral data. They are called isomorphic if $F$ is a composition of $f$ and some isomorphism $U$ of $H$ onto itself. We consider isomorphic inverse problems for ZS-operators on the unit interval under basic boundary conditions and on the circle. The proof is based on the non-linear analysis and properties of the 4-spectra mapping constructed in our paper.