Nuprl Lemma : select_l_index

∀[T:Type]. ∀[dT:EqDecider(T)]. ∀[L:T List]. ∀[x:T].  L[index(L;x)] = x ∈ T supposing (x ∈ L)


Proof




Definitions occuring in Statement :  l_index: index(L;x),  l_member: (x ∈ l),  select: L[n],  list: T List,  deq: EqDecider(T),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  prop: ℙ,  l_index: index(L;x),  deq: EqDecider(T),  int_seg: {i..j-},  guard: {T},  lelt: i ≤ j < k,  and: P ∧ Q,  all: ∀x:A. B[x],  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  implies: P ⇒ Q,  not: ¬A,  top: Top,  less_than: a < b,  squash: ↓T,  uiff: uiff(P;Q),  eqof: eqof(d),  so_lambda: λ2x.t[x],  so_apply: x[s],  l_member: (x ∈ l),  nat: ℕ,  le: A ≤ B,  cand: A c∧ B,  ge: i ≥ j ,  subtype_rel: A ⊆r B,  true: True,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  l_member_wf,  list_wf,  deq_wf,  mu-bound-property,  length_wf_nat,  select_wf,  int_seg_properties,  length_wf,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma,  int_seg_wf,  safe-assert-deq,  assert_wf,  eqof_wf,  exists_wf,  equal_wf,  lelt_wf,  nat_properties,  deq_property,  l_index_wf,  non_neg_length,  squash_wf,  true_wf,  iff_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  hypothesis,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  cumulativity,  hypothesisEquality,  sqequalRule,  isect_memberEquality,  axiomEquality,  because_Cache,  equalityTransitivity,  equalitySymmetry,  universeEquality,  lambdaEquality,  applyEquality,  setElimination,  rename,  independent_isectElimination,  natural_numberEquality,  productElimination,  dependent_functionElimination,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  voidElimination,  voidEquality,  independent_pairFormation,  computeAll,  imageElimination,  addLevel,  existsFunctionality,  levelHypothesis,  existsLevelFunctionality,  dependent_set_memberEquality,  applyLambdaEquality,  independent_functionElimination,  imageMemberEquality,  baseClosed

Latex:
\mforall{}[T:Type].  \mforall{}[dT:EqDecider(T)].  \mforall{}[L:T  List].  \mforall{}[x:T].    L[index(L;x)]  =  x  supposing  (x  \mmember{}  L)



Date html generated: 2017_04_17-AM-09_15_59
Last ObjectModification: 2017_02_27-PM-05_21_24

Theory : decidable!equality


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