theory SingleLet
imports "../Parser"
begin

atom_decl name

ML {* val _ = recursive := false *}

nominal_datatype trm =
  Var "name"
| App "trm" "trm"
| Lam x::"name" t::"trm"  bind x in t
| Let a::"assg" t::"trm"  bind "bn a" in t
and assg =
  As "name" "trm"
binder
  bn::"assg \<Rightarrow> atom set"
where
  "bn (As x t) = {atom x}"

print_theorems
thm alpha_trm_raw_alpha_assg_raw_alpha_bn_raw.intros[no_vars]

thm trm_assg.fv
thm trm_assg.supp
thm trm_assg.eq_iff[simplified alphas_abs[symmetric]]
thm trm_assg.bn
thm trm_assg.perm
thm trm_assg.induct
thm trm_assg.inducts
thm trm_assg.distinct
ML {* Sign.of_sort @{theory} (@{typ trm}, @{sort fs}) *}
thm trm_assg.fv[simplified trm_assg.supp]

end