  Problem of an adaptive state observer design for nonlinear system with
unknown time-varying parameters and under condition of delayed measurements is
considered. State observation problem was raised by many researchers (see for
example Sanx et al. (2019)). In this paper the results proposed in Bobtsov et
al. (2021b), Bobtsov et al. (2021a), Bobtsov et al. (2022a), Bobtsov et al.
(2022b) are developed. The problem is solved under assumption that the state
matrix can be represented as sum of known and unknown parts. The output vector
is measured with a known constant delay. An adaptive observer which
reconstructs unknown state and unknown time-varying parameter is proposed.
