Set up an illegal position with Houdini 4

Hello there :) ! I can't succeed to set up an illegal position with Houdini 4 (using Fritz interface I think). As an example I would like a position without kings. Is it possible to do that ? If the answer is yes, feel free to explain me how to do it. If the answer is no, which software should I use to reach my objective ? Thank you, S.

You can't.

Illegal chess positions are no chess positions. An interface (or engine) allowing them would be broken.

I just succeed this morning with chessbase 13 :)

Still waiting if there is an expert knowing how to do it with Houdini 4 ...

Hmmm...If Illegal chess positions aren't chess positions why do we use the term 'chess' to classify them?

Of course, you can.

Just about all of Otto Blathy's many-move chess problems' starting positions are obviously illegal, yet I have had various engines "infinitely" analyzing them. (To absolutely no avail, after up to a week of running non-stop, I might add, while people can solve these problems, and often fairly quickly.)

A position without two kings on the board is not a chess position at all.

You can set up illegal positions with the Aquarium interface, as below. 

but you should be able to do so. if you want to demonstrate a concept, eg opposition, knight maneouvring, pawn chains, etc you should be able to do so without including the kings. an engine or chess software should allow that.

I don't know why the OP wants that capability but it might be useful for chess publishing.  You could simply show how a piece moves or maybe a simple mate ---->>

To my surprise, Arena will also allow setup of illegal positions.

I wouldn't count on engines behaving normally with no kings on the board, but at least you can enter the position.

Thanks for the feedback

does aquarium allow you to add other UCI engines?  like stockfish?

Yes, you can add both UCI and Winboard engines.

Calling them illegal positions would be to vague.