Schematic representation of a general bow tie architecture. Input signals conveyed through the fan in (left) are widely diversified. The capacity to admit this variability confers flexibility and robustness on the system. Then, in the core, inputs (and information complexity) are 'compressed' by relatively rigid rules and protocols, and processed into basic modular building blocks. In the core, critical decisions about the sorting and the fate of the system outputs are taken. Finally, again through protocols, a variety of elaborated output fans out, and the complexity of the original, uncompressed information is restored. Output → input feedback loops may also occur.