The European Union must move from the formulation of rules on artificial intelligence to their operational implementation, President Sergio Mattarella said Wednesday.     "Our countries must strengthen the innovation ecosystem," said Mattarella, speaking at the COTEC (innovation society)Europa Symposium, where the presidents of the Italian, Spanish, and Portuguese COTECs signed a memorandum on artificial intelligence.     "The EU must make a leap. It must move from the formulation of principles