About the Authors

Davide Chiarugi

Affiliation Dipartimento di Matematica e Informatica, Università di Siena, Siena, Italy

Pierpaolo Degano

Affiliation Dipartimento di Informatica, Università di Pisa, Pisa, Italy

Roberto Marangoni

To whom correspondence should be addressed. E-mail: marangon@di.unipi.it

Affiliation Dipartimento di Informatica, Università di Pisa, Pisa, Italy

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

We warmly thank the referees for their invaluable suggestions and comments. DC and RM conceived and designed the experiments. DC performed the experiments. DC, PD, and RM analyzed the data and wrote the paper.