We would like to thank Daniel Jackson for the helpful discussions about the Electrum syntax and semantics and for suggesting some of the examples used in this book.

This work was financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia, within project POCI-01-0145-FEDER-016826.