Your dog obviously doesn't know Lisp :) Lisp allows any characters in a name (although some characters need to be escaped). So for example, I have a class cal

Your dog obviously doesn't know Lisp :) Lisp allows any characters in a name (although some characters need to be escaped). So for example, I have a class called "2-relation" (because I thought "binary-relation" was too long). The use of dashes in names is routine in Lisp; names beginning with digits are not so common, but are perfectly legal. And yes, though it's not the traditional style, some Lispers (including me) end the names of predicates (boolean-valued functions) with question marks.