Let $K$ be a field of characteristic$p>0$, $K[[x]]$, the ring of formal power series over $ K$,$K((x))$, the quotient field of $ K[[x]]$, and $ K(x)$ the fieldof rational functions over $K$. We shall give somecharacterizations of an algebraic function $fin K((x))$ over $K$.Let $L$ be a field of characteristic zero. The power series $finL[[x]]$ is called differentially algebraic, if it satisfies...

the book titled “bases of politics” is the original text for students of bachelor of political sciences which is taught in a three-unit course. this compilation has been introduced as the best reference for bases of politics course and master of science exam. we first introduce this text and assert its assumptions and then evaluate and criticize in contain and formal manner and finally after pr...