Genetic programming with semantic equivalence classes

Research output: Contribution to journalArticle

4 Citations (Scopus)


In this paper, we introduce the concept of semantics-based equivalence classes for symbolic regression problems in genetic programming. The idea is implemented by means of two different genetic programming systems, in which two different definitions of equivalence are used. In both systems, whenever a solution in an equivalence class is found, it is possible to generate any other solution in that equivalence class analytically. As such, these two systems allow us to shift the objective of genetic programming: instead of finding a globally optimal solution, the objective is now to find any solution that belongs to the same equivalence class as a global optimum. Further, we propose improvements to these genetic programming systems in which, once a solution that belongs to a particular equivalence class is generated, no other solution in that class is accepted in the population during the evolution anymore. We call these improved versions filtered systems. Experimental results obtained via seven complex real-life test problems show that using equivalence classes is a promising idea and that filters are generally helpful for improving the systems' performance. Furthermore, the proposed methods produce individuals with a much smaller size with respect to geometric semantic genetic programming. Finally, we show that filters are also useful to improve the performance of a state-of-the-art method, not explicitly based on semantic equivalence classes, like linear scaling.

Original languageEnglish
Pages (from-to)453-469
Number of pages17
JournalSwarm and Evolutionary Computation
Issue numberFebruary
Early online date1 Jan 2018
Publication statusPublished - Feb 2019


  • Equivalence classes
  • Genetic programming
  • Semantics

Fingerprint Dive into the research topics of 'Genetic programming with semantic equivalence classes'. Together they form a unique fingerprint.

  • Cite this