By investigating the properties of the natural state, this book presents
an analysis of input-output systems with regard to the mathematical
concept of state. The state of a system condenses the effects of past
inputs to the system in a useful manner. This monograph emphasizes two
main properties of the natural state; the first has to do with the
possibility of determining the input-output system from its natural
state set and the second deals with differentiability properties
involving the natural state inherited from the input-output system,
including differentiability of the natural state and natural state
trajectories. The results presented in this title aid in modeling
physical systems since system identification from a state set holds in
most models. Researchers and engineers working in electrical, aerospace,
mechanical, and chemical fields along with applied mathematicians
working in systems or differential equations will find this title useful
due to its rigorous mathematics.