Nuprl Lemma : member-reverse

∀[T:Type]. ∀L:T List. ∀x:T.  ((x ∈ rev(L)) ⇐⇒ (x ∈ L))


Proof




Definitions occuring in Statement :  l_member: (x ∈ l),  reverse: rev(as),  list: T List,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  l_member: (x ∈ l),  exists: ∃x:A. B[x],  cand: A c∧ B,  member: t ∈ T,  prop: ℙ,  rev_implies: P ⇐ Q,  squash: ↓T,  nat: ℕ,  int_seg: {i..j-},  lelt: i ≤ j < k,  le: A ≤ B,  true: True,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  guard: {T},  top: Top,  so_lambda: λ2x.t[x],  so_apply: x[s],  sq_stable: SqStable(P),  subtract: n - m,  uiff: uiff(P;Q),  nat_plus: ℕ+,  less_than: a < b,  less_than': less_than'(a;b),  not: ¬A,  false: False,  ge: i ≥ j ,  decidable: Dec(P),  or: P ∨ Q,  sq_type: SQType(T)
Lemmas referenced :  l_member_wf,  reverse_wf,  list_wf,  equal_wf,  squash_wf,  true_wf,  select-reverse,  lelt_wf,  length_wf,  iff_weakening_equal,  length-reverse,  subtract_wf,  non_neg_length,  length_wf_nat,  nat_wf,  set_subtype_base,  le_wf,  int_subtype_base,  less_than_wf,  select_wf,  sq_stable__le,  add-associates,  minus-one-mul,  add-swap,  add-commutes,  less-iff-le,  add_functionality_wrt_le,  le_reflexive,  minus-one-mul-top,  one-mul,  add-mul-special,  two-mul,  mul-distributes-right,  zero-mul,  add-zero,  not-le-2,  minus-zero,  zero-add,  omega-shadow,  mul-distributes,  mul-associates,  le-add-cancel,  not-lt-2,  minus-add,  minus-minus,  nat_properties,  decidable__le,  decidable__lt,  subtype_base_sq
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  independent_pairFormation,  sqequalHypSubstitution,  productElimination,  thin,  cut,  introduction,  extract_by_obid,  isectElimination,  cumulativity,  hypothesisEquality,  hypothesis,  universeEquality,  applyEquality,  lambdaEquality,  imageElimination,  equalityTransitivity,  equalitySymmetry,  because_Cache,  setElimination,  rename,  dependent_set_memberEquality,  natural_numberEquality,  sqequalRule,  imageMemberEquality,  baseClosed,  independent_isectElimination,  independent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  dependent_pairFormation,  sqequalIntensionalEquality,  intEquality,  dependent_functionElimination,  promote_hyp,  productEquality,  addLevel,  addEquality,  multiplyEquality,  levelHypothesis,  minusEquality,  unionElimination,  instantiate

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}x:T.    ((x  \mmember{}  rev(L))  \mLeftarrow{}{}\mRightarrow{}  (x  \mmember{}  L))



Date html generated: 2017_04_14-AM-08_40_40
Last ObjectModification: 2017_02_27-PM-03_31_13

Theory : list_0


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