Nuprl Lemma : no_repeats_cons

∀[T:Type]. ∀[l:T List]. ∀[x:T].  uiff(no_repeats(T;[x / l]);no_repeats(T;l) ∧ (¬(x ∈ l)))


Proof




Definitions occuring in Statement :  no_repeats: no_repeats(T;l),  l_member: (x ∈ l),  cons: [a / b],  list: T List,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  not: ¬A,  and: P ∧ Q,  universe: Type
Definitions unfolded in proof :  no_repeats: no_repeats(T;l),  all: ∀x:A. B[x],  member: t ∈ T,  top: Top,  uall: ∀[x:A]. B[x],  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  not: ¬A,  implies: P ⇒ Q,  false: False,  nat: ℕ,  sq_stable: SqStable(P),  squash: ↓T,  prop: ℙ,  true: True,  less_than': less_than'(a;b),  le: A ≤ B,  subtype_rel: A ⊆r B,  subtract: n - m,  rev_implies: P ⇐ Q,  iff: P ⇐⇒ Q,  or: P ∨ Q,  decidable: Dec(P),  guard: {T},  l_member: (x ∈ l),  exists: ∃x:A. B[x],  cand: A c∧ B,  select: L[n],  cons: [a / b],  sq_type: SQType(T),  label: ...$L... t
Lemmas referenced :  length_of_cons_lemma,  istype-void,  select_wf,  sq_stable__le,  not_wf,  equal_wf,  nat_wf,  less_than_wf,  length_wf,  l_member_wf,  cons_wf,  list_wf,  le_antisymmetry_iff,  not-equal-2,  decidable__equal_int,  le-add-cancel2,  less-iff-le,  not-lt-2,  decidable__lt,  le_wf,  le-add-cancel,  add-zero,  add_functionality_wrt_le,  add-commutes,  add-swap,  add-associates,  minus-one-mul-top,  zero-add,  minus-one-mul,  minus-add,  condition-implies-le,  not-le-2,  false_wf,  decidable__le,  squash_wf,  true_wf,  select_cons_tl,  iff_weakening_equal,  istype-false,  istype-int,  int_subtype_base,  subtract_wf,  minus-minus,  subtype_rel_self,  minus-zero,  le-add-cancel-alt,  subtype_base_sq
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  Error :isect_memberEquality_alt,  voidElimination,  hypothesis,  Error :isect_memberFormation_alt,  independent_pairFormation,  Error :lambdaFormation_alt,  independent_functionElimination,  Error :equalityIsType1,  Error :inhabitedIsType,  hypothesisEquality,  isectElimination,  cumulativity,  setElimination,  rename,  because_Cache,  independent_isectElimination,  natural_numberEquality,  imageMemberEquality,  baseClosed,  imageElimination,  Error :lambdaEquality_alt,  Error :universeIsType,  equalityTransitivity,  equalitySymmetry,  productElimination,  independent_pairEquality,  Error :isectIsType,  addEquality,  Error :productIsType,  universeEquality,  applyLambdaEquality,  minusEquality,  intEquality,  voidEquality,  isect_memberEquality,  lambdaEquality,  applyEquality,  lambdaFormation,  unionElimination,  dependent_set_memberEquality,  Error :dependent_set_memberEquality_alt,  Error :equalityIsType4,  instantiate,  Error :dependent_pairFormation_alt,  promote_hyp

Latex:
\mforall{}[T:Type].  \mforall{}[l:T  List].  \mforall{}[x:T].    uiff(no\_repeats(T;[x  /  l]);no\_repeats(T;l)  \mwedge{}  (\mneg{}(x  \mmember{}  l)))



Date html generated: 2019_06_20-PM-00_42_15
Last ObjectModification: 2018_10_01-PM-10_15_57

Theory : list_0


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