Writing a program to solve a problem is a process that can be divided into two phases: first, we invent a mental model of the solution; secondly, we map the mental model onto a physical representation. The mental model is multidimensional and syntax-free; in today’s textual programming languages, the physical representation is singledimensional and syntax-burdened. In fact, it hasn’t changed gr...

We consider solutions to the Euler equations in the whole space from a certain class, which can be characterized, in particular, by finiteness of mass, total energy and momentum. We prove that for a large class of right-hand sides, including the viscous term, such solutions, no matter how smooth initially, develop a singularity within a finite time. We find a sufficient condition for the singul...

0 binary, I-binary: The binary GCD algorithm ([lS]) and its improvement for multidigit integers (Gosper, see [12]). We compare the executron times of several algoixtliiiis for computing the G‘C‘U of arbitrary precasion iirlegers. These algorithms are the known ones (Euclidean, brnary, plus-mrnus), and the improved variants of these for multidigit compzltation (Lehmer and similar), as well as ne...

In this paper we give convex-ear decompositions for the order complexes of several classes of posets, namely supersolvable lattices with non-zero Möbius functions and rank-selected subposets of such lattices, rank-selected geometric lattices, and rank-selected face posets of shellable complexes which do not include the top rank. These decompositions give us many new inequalities for the h-vecto...

the malmquist productivity index evaluates the productivity change of a decision making unit (dmu) between two time periods. in this current study, a method is proposed to compute the malmquist productivity index in several time periods (from the first to the last periods) in data envelopment analysis (dea) and then, the obtained malmquist productivity index is compared with malmquist productiv...