“Certified complexity (CerCo)”, joint work with Roberto Amadio, Nicolas Ayache, Francois Bobot, Jaap Boender, Brian Campbell, Ilias Garnier, Antoine Madet, James McKinna, Dominic Mulligan, Mauro Piccolo, Randy Pollack, Yann Regis-Gianas, Claudio Sacerdoti Coen, Ian Stark and Paolo Tranquilli. To appear in the postproceedings of the third international workshop on Foundational and Practical Aspects of Resource Analysis (FOPARA) 2013.