Universal Induction with Varying Sets of Combinators
  Universal induction is a crucial issue in AGI. Its practical applicability
can be achieved by the choice of the reference machine or representation of
algorithms agreed with the environment. This machine should be updatable for
solving subsequent tasks more efficiently. We study this problem on an example
of combinatory logic as the very simple Turing-complete reference machine,
which enables modifying program representations by introducing different sets
of primitive combinators. Genetic programming system is used to search for
combinator expressions, which are easily decomposed into sub-expressions being
recombined in crossover. Our experiments show that low-complexity induction or
prediction tasks can be solved by the developed system (much more efficiently
than using brute force); useful combinators can be revealed and included into
the representation simplifying more difficult tasks. However, optimal sets of
combinators depend on the specific task, so the reference machine should be
adaptively chosen in coordination with the search engine.
