@ARTICLE {, title = {Matematické nástroje}, author = {Vrábel, Peter}, journal = {Obzory matematiky, fyziky a informatiky}, year = {2009}, volume = {38}, number = {2}, pages = {11--15}, issn = {1335-4981}, abstract = {A semi-invariant is the quantity which is changed monotonically and gains only finite values. Semi-invariants are often used in the analysis of evolving systems to show that certain final configurations must occur. Every investigated object of a problem is assigned some value of quantity and is defined a suitable operation on the set of objects. We concentrate on the least"or the greatest value of semi-invariant and we the problem solve by its means.}, } |