We propose a study of the modes of derivation of higher-order recursion
schemes, proving that value trees obtained from schemes using
innermost-outermost derivations (IO) are the same as those obtained using
unrestricted derivations. Given that higher-order recursion schemes can be used
as a model of functional programs, innermost-outermost derivations policy
represents a theoretical view point of call by value evaluation strategy.Comment: In Proceedings FICS 2012, arXiv:1202.317
