The paper reports on the CELLAS 2.1 system, whose main goal is the functional simulation of cellular processors. CELLAS 2.1 is a successor to the original CELLAS, a general-purpose cellular programming language proposed by T. Legendi. The main body of the paper gives a brief description of two major components of the system: the transition function definition subsystem and the cellular space simulator. These subsystems are linked through CELLAS libraries, and each subsystem is supported by its own compiler. Compilers are written using the so-called HLP/SZ system, which is the first Hungarian version of the Helsinki Language Processor.

One of the most interesting ideas used for transition function representation is organizing a transition table in the reduced state form, thereby avoiding excessive complexity of the next state computation. Another attractive feature is the use of conversion functions that map the states of cells onto the string of valuable data that is displayed to the user during the simulation process.

The weakest (but at the same time most impressive) points in the report are examples. The first example is too sketchy. It shows how a 3-D cellular space can be simulated by 2-D cellular field simulation. But some readers (I hope not everyone) may only wonder what is meant by a “generalized teletransport facility” reportedly achieved through a “neighborhood” treatment. In the second example, the transition function for a multiplier cell is defined in the accepted notation. However, the figure displaying the snapshot of the 5 × 13 (as stated in the caption) multiplication contains a small flaw: the binary representation of the first multiplicand is shown as 1100, which equals twelve and not five. This is of course just a funny bug rather than an error, but I would like to express my appreciation of this sort of bug. As a matter of fact, the positive and even instructive role of such bugs in papers’ examples (when, of course, confined to the examples) is immense because they give the reader a chance to gain more confidence in his or her understanding of a text by being implicit exercises: is this curious discrepancy a flaw or not? Without them, reading would be a more tedious process.

By and large, the paper leaves a good impression and will cetainly be of interest for both cellular structure designers and high-level hardware description language constructors.