Nuprl Lemma : firstn_nth_tl_decomp

∀[T:Type]. ∀[L:T List]. ∀[i:ℕ||L||].  (L ~ firstn(i;L) @ [L[i]] @ nth_tl(1 + i;L))


Proof




Definitions occuring in Statement :  firstn: firstn(n;as),  select: L[n],  length: ||as||,  nth_tl: nth_tl(n;as),  append: as @ bs,  cons: [a / b],  nil: [],  list: T List,  int_seg: {i..j-},  uall: ∀[x:A]. B[x],  add: n + m,  natural_number: $n,  universe: Type,  sqequal: s ~ t
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  append: as @ bs,  all: ∀x:A. B[x],  so_lambda: so_lambda(x,y,z.t[x; y; z]),  top: Top,  so_apply: x[s1;s2;s3],  subtype_rel: A ⊆r B,  uimplies: b supposing a,  le: A ≤ B,  and: P ∧ Q,  less_than': less_than'(a;b),  false: False,  not: ¬A,  implies: P ⇒ Q,  prop: ℙ,  int_seg: {i..j-},  lelt: i ≤ j < k,  decidable: Dec(P),  or: P ∨ Q,  less_than: a < b,  squash: ↓T,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x]
Lemmas referenced :  list_wf,  int_seg_wf,  lelt_wf,  int_formula_prop_wf,  int_term_value_constant_lemma,  int_term_value_add_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermConstant_wf,  itermAdd_wf,  itermVar_wf,  intformless_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__lt,  top_wf,  subtype_rel_list,  append_firstn_lastn_sq,  int_seg_properties,  false_wf,  length_wf,  int_seg_subtype_nat,  nth_tl_decomp,  list_ind_nil_lemma,  list_ind_cons_lemma
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  lemma_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isect_memberEquality,  voidElimination,  voidEquality,  hypothesis,  isectElimination,  hypothesisEquality,  applyEquality,  natural_numberEquality,  independent_isectElimination,  independent_pairFormation,  lambdaFormation,  setElimination,  rename,  productElimination,  lambdaEquality,  because_Cache,  dependent_set_memberEquality,  addEquality,  unionElimination,  imageElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  computeAll,  cumulativity,  sqequalAxiom,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}[L:T  List].  \mforall{}[i:\mBbbN{}||L||].    (L  \msim{}  firstn(i;L)  @  [L[i]]  @  nth\_tl(1  +  i;L))



Date html generated: 2016_05_14-PM-02_07_57
Last ObjectModification: 2016_01_15-AM-08_03_15

Theory : list_1


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