A theorem, also called the iteration theorem, that makes use of the lambda notation introduced by Church. Let denote the recursive
function of
variables with Gödel number
(where (1) is normally omitted). Then for every
and
, there exists a primitive
recursive function
such that for all
,
, ...,
,
A direct application of the -
-
theorem is the fact that there exists a primitive
recursive function
such that
for all
and
.
The -
-
theorem is applied in the proof of the recursion theorem.
The
-
-
theorem is the theoretical premise for a branch of computer
science known as partial evaluation.