Abstract When are two germs of analytic systems conjugate or orbitally equivalent under an change coordinates in a neighborhood singular point? The present paper, survey nature, presents research program around this question. A way to answer is use normal forms. However, there large classes dynamical for which the form diverges. In we discuss case singularities normalizing transformation k -sum...

The purpose of this study is to discuss the validity equivalence in sample groups young and adult; females males scale assessing attitudes towards foreign language skills offer researchers that will use certain evidence based on data. No measurement equivalence/invariance was found adult groups. Consequently, gender variable not present, either. absence fact a fundamental proof instrument speci...