updated to latest changes (10 April) to quotient package (lift_raw_const only takes dummy theorem TrueI....in the future this will not work anymore)
theory Sigma
imports Nominal2
begin
atom_decl name
nominal_datatype obj =
Var name
| Obj smlst
| Inv obj string
| Upd obj string method
and smlst =
SMNil
| SMCons string method smlst
and method =
Sig n::name o::obj binds n in o
end