Class Dictionary: RepetitionClass = "~" Sandwich(UNKNOWN1). RepeatedPart = [ UNKNOWN2 ] "{" UNKNOWN3(ClassSpec) "}". UNKNOWN4(S) = List(UNKNOWN5) UNKNOWN6 List(UNKNOWN7) . ClassSpec = ClassName. UNKNOWN8 = String. ClassName = Ident. Inputs: A1 ~ {B}. A2 ~ "x" {B} "y". A3 ~ "x" "(" {"r" "g" B "s"}"l" "k" "y". A4 ~ "x" B {"r" B "s" "g"} "y" "z". A5 ~ "{" B {"," B} "}".