Instance EqDec_statement: EqDec statement := eq_dec_statement.
Instance EqDec_external_function: EqDec external_function := eq_dec_external_function.

Lemma closed_Sswitch e sl F:
closed_wrt_modvars (Sswitch e sl) F ->
(forall n, closed_wrt_modvars (seq_of_labeled_statement (select_switch (Int.unsigned n) sl)) F).