And there was I, a Latin scholar and a pedant, thinking I was being clever!!
It's a common misconception that we don't have a constitution, but we have many bits and pieces of one, starting with the Magna Carta, going down through the ages to the Bill and Claim of Rights, and so on. What those judges (dubbed 'The Enemies Of The People' by that "august organ" the Mail, qua The Nazis in the 1930s) ruled on in early 2017, was that Parliament had a constitutional right to have a say throughout the Brexit process.