Nuprl Lemma : nth_tl_factor

T:Type. ∀n:ℕ. ∀as:T List.  ((n ≤ ||as||)  (nth_tl(n;as) (Π n ≤ i < ||as||. [as[i]]) ∈ (T List)))


Proof




Definitions occuring in Statement :  lapp_imon: <List,@> select: L[n] length: ||as|| nth_tl: nth_tl(n;as) cons: [a b] nil: [] list: List nat: le: A ≤ B all: x:A. B[x] implies:  Q universe: Type equal: t ∈ T mon_itop: Π lb ≤ i < ub. E[i]
Definitions unfolded in proof :  all: x:A. B[x] nth_tl: nth_tl(n;as) member: t ∈ T uall: [x:A]. B[x] implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a ifthenelse: if then else fi  prop: bfalse: ff guard: {T} subtract: m le_int: i ≤j lt_int: i <j bnot: ¬bb less_than: a < b squash: T less_than': less_than'(a;b) false: False subtype_rel: A ⊆B not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] top: Top so_lambda: λ2x.t[x] int_seg: {i..j-} lelt: i ≤ j < k decidable: Dec(P) or: P ∨ Q so_apply: x[s] nat: ge: i ≥  le: A ≤ B true: True iff: ⇐⇒ Q rev_implies:  Q imon: IMonoid list: List grp_car: |g| pi1: fst(t) lapp_imon: <List,@>
Lemmas referenced :  le_int_wf uiff_transitivity equal-wf-base bool_wf assert_wf le_wf eqtt_to_assert assert_of_le_int length_wf list_wf lt_int_wf less_than_wf bnot_wf eqff_to_assert assert_functionality_wrt_uiff bnot_of_le_int assert_of_lt_int int_subtype_base full-omega-unsat intformand_wf intformle_wf itermVar_wf itermConstant_wf intformless_wf istype-int int_formula_prop_and_lemma istype-void int_formula_prop_le_lemma int_term_value_var_lemma int_term_value_constant_lemma int_formula_prop_less_lemma int_formula_prop_wf subtract_wf nth_tl_wf mon_itop_wf lapp_imon_wf cons_wf select_wf int_seg_properties decidable__le intformnot_wf itermSubtract_wf int_formula_prop_not_lemma int_term_value_subtract_lemma decidable__lt nil_wf int_seg_wf primrec-wf2 all_wf equal_wf nat_properties nat_wf lapp_fact_b squash_wf true_wf istype-universe tl_wf length_tl iff_weakening_equal subtype_rel_self grp_car_wf imon_wf select_tl imon_subtype_grp_sig itermAdd_wf int_term_value_add_lemma add-associates add-swap add-commutes zero-add mon_itop_shift
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt cut thin sqequalRule introduction extract_by_obid sqequalHypSubstitution isectElimination natural_numberEquality hypothesis inhabitedIsType unionElimination equalityElimination baseClosed independent_functionElimination because_Cache productElimination independent_isectElimination universeIsType hypothesisEquality imageElimination voidElimination equalityIsType1 equalityTransitivity equalitySymmetry dependent_functionElimination rename setElimination baseApply closedConclusion applyEquality approximateComputation dependent_pairFormation_alt lambdaEquality_alt int_eqEquality isect_memberEquality_alt independent_pairFormation functionIsType setIsType functionEquality universeEquality imageMemberEquality instantiate dependent_set_memberEquality_alt productIsType addEquality

Latex:
\mforall{}T:Type.  \mforall{}n:\mBbbN{}.  \mforall{}as:T  List.    ((n  \mleq{}  ||as||)  {}\mRightarrow{}  (nth\_tl(n;as)  =  (\mPi{}  n  \mleq{}  i  <  ||as||.  [as[i]])))



Date html generated: 2019_10_16-PM-01_05_32
Last ObjectModification: 2018_10_08-AM-10_53_40

Theory : list_2


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