Abstract

Unimodular equivalence (UE) is defined for matrix fraction decompositions (MFDs). It is shown that if an MFD is regarded as a quadruple {D(s), N(s(, I. ()}, then uni-modular equivalence and (Fuhrmann) strict system equivalence coincide. It is thus established that UE for MFDs and system similarity for state-space representations are exact counterparts. A brief discussion on extended unimodular equivalence (EUE) of polynomial matrices is included and a short polynomial matrix proof that the invariant factors of the Smith form are preserved under EUE is given.