Nuprl Lemma : l_member-alt-def

∀[T:Type]. ∀L:T List. ∀x:T.  ((x ∈ L) ⇐⇒ ∃i:ℕ||L||. (x = L[i] ∈ T))


Proof




Definitions occuring in Statement :  l_member: (x ∈ l),  select: L[n],  length: ||as||,  list: T List,  int_seg: {i..j-},  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  natural_number: $n,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  l_member: (x ∈ l),  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  exists: ∃x:A. B[x],  member: t ∈ T,  nat: ℕ,  int_seg: {i..j-},  lelt: i ≤ j < k,  prop: ℙ,  cand: A c∧ B,  uimplies: b supposing a,  guard: {T},  ge: i ≥ j ,  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  not: ¬A,  top: Top,  less_than: a < b,  squash: ↓T,  so_lambda: λ2x.t[x],  so_apply: x[s],  rev_implies: P ⇐ Q,  subtype_rel: A ⊆r B,  le: A ≤ B,  less_than': less_than'(a;b)
Lemmas referenced :  lelt_wf,  equal_wf,  select_wf,  int_seg_properties,  length_wf,  nat_properties,  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,  exists_wf,  nat_wf,  less_than_wf,  int_seg_subtype_nat,  false_wf,  int_seg_wf,  list_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  lambdaFormation,  independent_pairFormation,  sqequalHypSubstitution,  productElimination,  thin,  dependent_pairFormation,  setElimination,  rename,  dependent_set_memberEquality,  hypothesisEquality,  hypothesis,  cut,  introduction,  extract_by_obid,  isectElimination,  because_Cache,  addLevel,  levelHypothesis,  independent_isectElimination,  natural_numberEquality,  cumulativity,  dependent_functionElimination,  unionElimination,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  imageElimination,  productEquality,  applyEquality,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}x:T.    ((x  \mmember{}  L)  \mLeftarrow{}{}\mRightarrow{}  \mexists{}i:\mBbbN{}||L||.  (x  =  L[i]))



Date html generated: 2017_04_17-AM-07_25_28
Last ObjectModification: 2017_02_27-PM-04_04_19

Theory : list_1


Home Index