Summary: Big Random Tree Programs

• Above a threshold, distribution of performance is independent of tree size.

• Most trees are asymmetric. The chance of finding a leaf near the root is $\approx 50\%$. (Cf. some linear GP systems).

• Even if instruction set is symmetric, some functions are more likely than others.

• Solutions to problems where the function set requires them to be bushy will be rare.

• The number of solutions grows exponentially with size.