abstract = "Program Trace Optimization (PTO) is a framework that
provides automatic representation design by separating
problem specification from search algorithms. PTO
requires only a generator creating candidate solutions
and a fitness function, enabling any search algorithm
to address any problem through a universal solution
representation. A key strength is PTO ability to work
with unrestricted programs as generators. While
previously applied with simple random generators, we
now explore PTOs use with sophisticated generators to
search the space of Lambda calculus (LC) expressions.
LC serves as an ideal test case: a Turing-complete
minimal language underlying all functional programming.
Despite its simplicity, traditional Genetic Programming
and Grammatical Evolution struggle with LC
context-dependent nature. Additionally, non-trivial LC
programs require recursive expressions, which are
notoriously difficult to evolve. We demonstrate that
PTO naturally captures LC context-dependent aspects and
efficiently searches the space of valid LC expressions,
with its automatically designed operators proving well
suited for evolving recursive expressions.",