-- Lisp as used in the Alvey grammar entrypoints Prog, Exp ; Pro. Prog ::= [Exp] ; App. Exp ::= "(" [Exp] ")" ; At. Exp ::= Id ; IdPlus. Exp ::= IdPl ; IdStr. Exp ::= String ; Plus. Exp ::= "+" ; Minus. Exp ::= "-" ; Num. Exp ::= Integer ; token IdPl ('+' letter (letter | digit | '-' | '_')*) ; token Id (letter (letter | digit | '-' | '_')*) ; terminator Exp "" ; comment ";;" ;