Nuprl Lemma : nth_tl_decomp

[T:Type]. ∀[m:ℕ]. ∀[L:T List].  nth_tl(m;L) [L[m] nth_tl(1 m;L)] supposing m < ||L||


Proof




Definitions occuring in Statement :  select: L[n] length: ||as|| nth_tl: nth_tl(n;as) cons: [a b] list: List nat: less_than: a < b uimplies: supposing a uall: [x:A]. B[x] add: m natural_number: $n universe: Type sqequal: t
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T nat: implies:  Q false: False ge: i ≥  uimplies: supposing a not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] 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 subtract: m btrue: tt decidable: Dec(P) or: P ∨ Q squash: T less_than: a < b true: True subtype_rel: A ⊆B guard: {T} iff: ⇐⇒ Q rev_implies:  Q bool: 𝔹 unit: Unit it: uiff: uiff(P;Q) sq_type: SQType(T) assert: b select: L[n] nil: [] so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] cons: [a b]
Lemmas referenced :  nat_properties full-omega-unsat 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 length_wf list_wf decidable__le subtract_wf intformnot_wf itermSubtract_wf int_formula_prop_not_lemma int_term_value_subtract_lemma nat_wf list_decomp select0 tl_wf squash_wf true_wf length_tl subtype_rel_self iff_weakening_equal decidable__lt le_int_wf bool_wf eqtt_to_assert assert_of_le_int eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot le_wf non_neg_length itermAdd_wf int_term_value_add_lemma int_subtype_base list-cases reduce_tl_nil_lemma nth_tl_nil stuck-spread base_wf length_of_nil_lemma product_subtype_list reduce_tl_cons_lemma length_of_cons_lemma select-cons-tl
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 approximateComputation independent_functionElimination dependent_pairFormation lambdaEquality int_eqEquality intEquality dependent_functionElimination isect_memberEquality voidElimination voidEquality sqequalRule independent_pairFormation sqequalAxiom equalityTransitivity equalitySymmetry unionElimination because_Cache universeEquality applyEquality imageElimination productElimination imageMemberEquality baseClosed instantiate equalityElimination addEquality promote_hyp cumulativity hypothesis_subsumption

Latex:
\mforall{}[T:Type].  \mforall{}[m:\mBbbN{}].  \mforall{}[L:T  List].    nth\_tl(m;L)  \msim{}  [L[m]  /  nth\_tl(1  +  m;L)]  supposing  m  <  ||L||



Date html generated: 2018_05_21-PM-00_32_41
Last ObjectModification: 2018_05_19-AM-06_42_44

Theory : list_1


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