Because I recognized the Greek letter that we usually represent in English as “xi”. In fact I wasn’t sure, but I guessed x, and it turned out to be right. For e

Because I recognized the Greek letter that we usually represent in English as “xi”. In fact I wasn’t sure, but I guessed x, and it turned out to be right. For each letter there’s usually one obvious latin-alphabet equivalent. I bet you know right away how to type α and β.