The article develops the concept of building a library of tasks and their solutions in the form of computational processes (CPs) and Petri nets (PNs) with the preliminary transformation of CPs into PNs. The conversion includes the extraction of macro operations (MOs) from CPs as a result of their analysis, the construction of PNs and their fragments as models of CPs and MOs, and the modeling of PNs and their fragments. The architecture, structure and interface of the library are proposed. Computational process is a sequence of time-ordered operations and procedures of varying degrees of complexity. The set of PNs, as well as the set of problems for which PNs are solutions, is divided into classes and subclasses. A class includes problems such as Combinatorial, Linear Algebraic Equations, etc.; the Combinatorial class includes subclasses of problems such as Sorting, Search, Sets, Graphs, etc. A macro operation is a fragment of a GP that is a functionally complete computational construct. MOs can have different levels of complexity, starting with the elementary one; they can be built hierarchically. A Petri net is a bipartite graph with two interconnected objects: event-condition, process-resource, etc. Fragments of the PN are models of the MO. The components of the library are tree nodes supplemented with files of their verbal descriptions built according to certain rules. The architecture, structure, interface, and operations of the library provide convenient management, editing, and expansion of knowledge about computational processes and macro operations, making the library open for further research and development by the developer. All files are available to the user, but without the right to edit. The paper presents an example of the initial filling of the library for the Sorting task.