This paper focuses on the halting probability and the number of instructions executed by programs that halt for Turing-complete assembly-like languages and register based machines.

Abstract. Conventional genetic programming research excludes memory and iteration. We have begun an extensive analysis of the space through which GP or other unconventional AI approaches search and extend it to consider explicit program stop instructions (T8) and any time models (T7). We report halting probability, run time and functionality (including entropy of binary functions) of both halting and anytime programs. Turing complete program fitness landscapes, even with halt, scale poorly. 1

... Harvester), a methodology for evolving Java bytecode, enabling the evolution of extant, unrestricted Java programs, or programs in other languages that compile to Java bytecode. Our approach is based upon the notion of compatible crossover, which produces correct programs by performing operand stack-, local variables-, and control flow-based compatibility checks on source and destination bytecode sections. This is in contrast to existing work that uses restricted subsets of the Java bytecode instruction set as a representation language for individuals in genetic programming. We demonstrate FINCH’s unqualified success at solving a host of problems, including simple and complex regression, trail navigation, image classification, array sum, and tic-tac-toe. FINCH exploits the richness of the Java Virtual Machine architecture and type system, ultimately evolving human-readable solutions in the form of Java programs. The ability to evolve Java programs will hopefully lead to a valuable new tool in the software engineer’s toolkit.

Generating a random sampling of program trees with specified function and terminal sets is the initial step of many program evolution systems. I present a theoretical and experimental analysis of the expected distribution of uniformly sampled programs, guided by algorithmic information theory. This analysis demonstrates that increasing the sample size is often an inefficient means of increasing the overall diversity of program behaviors (outputs). A novel sampling scheme (semantic sampling) is proposed that exploits semantics to heuristically increase behavioral diversity. An important property of the scheme is that no calls of the problem-specific fitness function are required. Its effectiveness at increasing behavioral diversity is demonstrated empirically for Boolean formulae. Furthermore, it is found to lead to statistically significant improvements in performance for genetic programming on parity and multiplexer problems.

Generating a random sampling of program trees with specified function and terminal sets is the initial step of many program evolution systems. I present a theoretical and experimental analysis of the expected distribution of uniformly sampled programs, guided by algorithmic information theory. This analysis demonstrates that increasing the sample size is often an inefficient means of increasing the overall diversity of program behaviors (outputs). A novel sampling scheme (semantic sampling) is proposed that exploits semantics to heuristically increase behavioral diversity. An important property of the scheme is that no calls of the problem-specific fitness function are required. Its effectiveness at increasing behavioral diversity is demonstrated empirically for Boolean formulae. Furthermore, it is found to lead to statistically significant improvements in performance for genetic programming on parity and multiplexer problems.

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We describe Fertile Darwinian Bytecode Harvester

The established approach in genetic programming (GP) involves the definition of functions and terminals appropriate to the problem at hand, after which evolution of expressions using these definitions takes place. We have recently developed a system, dubbed FINCH (Fertile Darwinian Bytecode Harvester), to evolutionarily improve actual, extant software, which was not intentionally written for the purpose of serving as a GP representation in particular, nor for evolution in general. This is in contrast to existing work that uses restricted subsets of the Java bytecode instruction set as a representation language for individuals in genetic programming. The ability to evolve Java programs will hopefully lead to a valuable new tool in the software engineer’s toolkit. Java bytecode, automatic programming, software evolution, genetic programming.