Aspects and prospects of theoretical computer science : 6th International Meeting of Young Computer Scientists, Smolenice, Czechoslovakia, November 19-23, 1990 : proceedings

"This volume contains the texts of the tutorial lecture, five invited lectures and twenty short communications contributed for presentation at the Sixth International Meeting of Young Computer Scientists, IMYCS '90. The aim of these meetings is threefold: (1) to inform on newest trends, results, and problems in theoretical computer science and related fields through a tutorial and invited lectures delivered by internationally distinguished speakers, (2) to provide a possibility for beginners in scientific work to present and discuss their results, and (3) to create an adequate opportunity for establishing first professional relations among the participants."--Publisher's Website. Methods for generating deterministic fractals and image compression....Pages 1-28 Optimum simulation of meshes by small hypercubes....Pages 29-46 Seven hard problems in symbolic background knowledge acquisition....Pages 47-61 Subsequential functions: Characterizations, minimization, examples....Pages 62-79 Past proves more invariance properties but not pca's....Pages 80-92 Complexity issues in discrete neurocomputing....Pages 93-108 Two-way reading on words....Pages 109-119 Proofs and reachability problem for ground rewrite systems....Pages 120-129 Problems complete for ⊕L....Pages 130-137 Constructive matching — Explanation based methodology for inductive theorem proving....Pages 138-147 Characterizing complexity classes by higher type....Pages 148-158 The distributed termination problem : Formal solution and correctness based on petri nets....Pages 159-168 Greedy compression systems....Pages 169-176 A DIV(N) depth Boolean circuit for smooth modular inverse....Pages 177-183 Learning by conjugate gradients....Pages 184-194 Monoids described by pushdown automata....Pages 195-203 Optimal parallel 3-colouring algorithm for rooted trees and its application....Pages 204-213 Hierarchies over the context-free languages....Pages 214-224 A hierarchy of unary primitive recursive string-functions....Pages 225-233 Minimizing picture words....Pages 234-243 Remarks on the frequency-coded neural nets complexity....Pages 244-250 Picture generation using matrix systems....Pages 251-260 Representing heuristic-relevant information for an automated theorem prover....Pages 261-270 A new method for proving lower bounds in the model of algebraic decision trees....Pages 271-277 Area time squared and area complexity of VLSI computations is strongly unclosed under union and intersection....Pages 278-287 Decision procedure for checking validity of PAL formulas....Pages 288-298