- (CharVector.all (fn ch => (Char.isGraph ch) andalso not (List.exists (fn c => ch = c) [ #"[", #"]", #",", #"\"", #"'", #"=", #":" ])))
+ (CharVector.all (fn ch => (Char.isGraph ch) andalso not (List.exists (fn c => ch = c) [ #"[", #"]", #",", #"\"", #"'", #"=", #":", "\\" ])))