There is a gap between program languages theoreticians and practical programmers: the former are strong in science of Abstract Algebra and Formal Logic, the later – in the craft of software development. The paper sketches a very simple approach to algebraic and logic foundations of formal program semantics classification, an approach that should fit practical programmers just with rudimental experience in logic and algebra. In particular, paper presents operational, denotational, axiomatic and second-order semantics for a toy language (that just looks like a programming language).

The paper describes a mathematical model of submission documents. The model includes a description of different types of segments, which are defined in the text using markers. An algorithm for segmenting the document text is given for this model.

We discuss the possibility of studying processes based on their representation as development spirals. The geometric concepts related to the spiral are introduced. This allows modeling the development by projections of processes trajectories on different planes of the space factors.

Subdefinite Models is one of the methods to solve Constraint Satisfaction Problem. The base notion of the method is Sudefiniteness, which defines the set representation of inaccurate values. The paper contains formal definitions of different kinds of Sudefinitness, their comparisons, and descriptions of their properties.