split the files - Iteration.thy contains the big proof of the iteration combinator - Recursion.thy derives from Iteration the recursion combinator - lam_substs.thy contains the examples (size, substitution and parallel substitution)

Added in a signature.

fixed a problem where a permutation is not analysed when the term is of the form (pi o f) x1...xn This was the case because the head of this term is the constant "nominal.perm". Now an applicability predicate decides the right behaviour of the simproc