Nuprl Lemma : select-nthtl

[n:ℕ]. ∀[L:Top List].  (L[n] hd(nth_tl(n;L)))


Proof




Definitions occuring in Statement :  select: L[n] hd: hd(l) nth_tl: nth_tl(n;as) list: List nat: uall: [x:A]. B[x] top: Top sqequal: t
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T nat: implies:  Q false: False ge: i ≥  uimplies: supposing a satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] not: ¬A all: x:A. B[x] top: Top and: P ∧ Q prop: nth_tl: nth_tl(n;as) le_int: i ≤j lt_int: i <j bnot: ¬bb ifthenelse: if then else fi  bfalse: ff btrue: tt subtype_rel: A ⊆B guard: {T} or: P ∨ Q select: L[n] nil: [] it: so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] cons: [a b] colength: colength(L) decidable: Dec(P) so_lambda: λ2x.t[x] so_apply: x[s] sq_type: SQType(T) less_than: a < b squash: T less_than': less_than'(a;b) bool: 𝔹 unit: Unit uiff: uiff(P;Q) assert: b
Lemmas referenced :  nat_properties satisfiable-full-omega-tt intformand_wf intformle_wf itermConstant_wf itermVar_wf intformless_wf int_formula_prop_and_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_wf ge_wf less_than_wf list_wf top_wf equal-wf-T-base nat_wf colength_wf_list less_than_transitivity1 less_than_irreflexivity list-cases stuck-spread base_wf product_subtype_list spread_cons_lemma intformeq_wf itermAdd_wf int_formula_prop_eq_lemma int_term_value_add_lemma decidable__le intformnot_wf int_formula_prop_not_lemma le_wf equal_wf subtype_base_sq set_subtype_base int_subtype_base decidable__equal_int subtract_wf itermSubtract_wf int_term_value_subtract_lemma reduce_hd_cons_lemma nth_tl_nil hd-nil select-cons-tl le_int_wf bool_wf eqtt_to_assert assert_of_le_int eqff_to_assert bool_cases_sqequal bool_subtype_base assert-bnot reduce_tl_cons_lemma
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis setElimination rename intWeakElimination lambdaFormation natural_numberEquality independent_isectElimination dependent_pairFormation lambdaEquality int_eqEquality intEquality dependent_functionElimination isect_memberEquality voidElimination voidEquality sqequalRule independent_pairFormation computeAll independent_functionElimination sqequalAxiom because_Cache applyEquality unionElimination baseClosed promote_hyp hypothesis_subsumption productElimination equalityTransitivity equalitySymmetry applyLambdaEquality dependent_set_memberEquality addEquality instantiate cumulativity imageElimination equalityElimination

Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[L:Top  List].    (L[n]  \msim{}  hd(nth\_tl(n;L)))



Date html generated: 2017_04_17-AM-07_32_49
Last ObjectModification: 2017_02_27-PM-04_09_18

Theory : list_1


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