Definition main_params (ge: genv) start : Prop :=
  exists b, exists func,
    Genv.find_symbol ge start = Some b /\
        Genv.find_funct ge (Vptr b Ptrofs.zero) = Some (Internal func) /\
        func.(fn_params) = nil.

Lemma in_prog_funct_in_prog_defs: forall i f prog, In (i,f) (prog_funct prog) -> In (i, Gfun f) (prog_defs prog).