Nuprl Lemma : select_append

∀[T:Type]. ∀[as,bs:T List]. ∀[i:ℕ||as|| + ||bs||].  (as @ bs[i] = if i <z ||as|| then as[i] else bs[i - ||as||] fi  ∈ T)


Proof




Definitions occuring in Statement :  select: L[n],  length: ||as||,  append: as @ bs,  list: T List,  int_seg: {i..j-},  ifthenelse: if b then t else f fi ,  lt_int: i <z j,  uall: ∀[x:A]. B[x],  subtract: n - m,  add: n + m,  natural_number: $n,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  int_seg: {i..j-},  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  ifthenelse: if b then t else f fi ,  lelt: i ≤ j < k,  prop: ℙ,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  false: False,  decidable: Dec(P),  less_than: a < b,  squash: ↓T,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  top: Top
Lemmas referenced :  lt_int_wf,  length_wf,  bool_wf,  eqtt_to_assert,  assert_of_lt_int,  select_append_front,  lelt_wf,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  not_functionality_wrt_uiff,  assert_wf,  less_than_wf,  select_append_back,  decidable__le,  add-is-int-iff,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformle_wf,  itermVar_wf,  intformless_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  false_wf,  int_seg_wf,  list_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  setElimination,  rename,  hypothesisEquality,  hypothesis,  lambdaFormation,  unionElimination,  equalityElimination,  because_Cache,  productElimination,  independent_isectElimination,  sqequalRule,  dependent_set_memberEquality,  independent_pairFormation,  natural_numberEquality,  cumulativity,  dependent_pairFormation,  equalityTransitivity,  equalitySymmetry,  promote_hyp,  dependent_functionElimination,  instantiate,  independent_functionElimination,  voidElimination,  pointwiseFunctionality,  imageElimination,  baseApply,  closedConclusion,  baseClosed,  approximateComputation,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidEquality,  addEquality,  Error :universeIsType,  axiomEquality,  Error :inhabitedIsType,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}[as,bs:T  List].  \mforall{}[i:\mBbbN{}||as||  +  ||bs||].
    (as  @  bs[i]  =  if  i  <z  ||as||  then  as[i]  else  bs[i  -  ||as||]  fi  )



Date html generated: 2019_06_20-PM-01_19_45
Last ObjectModification: 2018_09_26-PM-05_20_43

Theory : list_1


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