```Hello,

I have been reading the ECJ-Interest list for a while, and I find it
really interesting...
I hope that my question is not too stupid, but I really have problems
I am trying to solve a system of n equations using an ADF implementation.

I managed to represent it as the following tree :
Master Tree
|
Result Producing Branch
|        |         |

If I generate a system containing 3 variables like :
(X1 = a variable given from a learning sample)
X2 = X1 + X1
X3 = X1 * X2

Where ADF0 corresponds to the equation establishing the value of X2 and
contains the X1 + X1 , and ADF1 corresponds to the value of X3 ands
contains X1*X2...

My problem is that, as ADF0 returns the value of X2 and  ADF1 returns the
value of X3,  I would like the result prucing branch to take these 2
inputs and return both values to the GP problem. So I have my ADF
returning a different type of variable (single variable) than the one used
in the GPproblem (multiple variables)...

Here is what I did:
producing branch, that would concatenate the result of each ADF into a 2
dimensional array, and an operator ONLY(ADF..) that would take the result
of one  ADF and return it under the format of the 2 dimensional array as
well...
Problem :
- The result producing branch gives me a very complicated tree of
unecessary lenght with a lot of ONLY and AND... Is there any way to just
have one operator that would take n ADF as input , and return a 2-
dimensional array of correponding size? And then limit the result
producing tree structure as having only one function with n Adfs.
In preparation for such an operator, I have added in the koza.params file
branching up to nc20 (20 variables!).

REsult-Producing Tree
|
ADFsReceptor -> return a 2-dimensional array of floats
/     |    \