Verónica Becher was Visiting Fellow Isaac Newton Institute for Mathematical Sciences , in the Program Semantics and Syntax – A Legacy of Alan Turing, Cambridge UK, 17 June-July 6, 2012. http://www.newton.ac.uk/SAS/Verónica Becher was Visiting Fellow Isaac Newton Institute for Mathematical Sciences , in the Program Semantics and Syntax – A Legacy of Alan Turing, Cambridge UK, 17 June-July 6, 2012. http://www.newton.ac.uk/SAS/Verónica Becher was Visiting Fellow Isaac Newton Institute for Mathematical Sciences , in the Program Semantics and Syntax – A Legacy of Alan Turing, Cambridge UK, 17 June-July 6, 2012. http://www.newton.ac.uk/SAS/