Nuprl Lemma : all-but-one

∀[T:Type]. ∀[P:T ⟶ ℙ].
  ∀L:T List
    (∀x,y:T.  Dec(x = y ∈ T))
    ⇒ ((∀x∈L.(∀y∈L.P[x] ∨ P[y] supposing ¬(x = y ∈ T))) ⇐⇒ (∃x∈L. (∀y∈L.P[y] supposing ¬(x = y ∈ T)))) 
    supposing 0 < ||L||


Proof




Definitions occuring in Statement :  l_exists: (∃x∈L. P[x]),  l_all: (∀x∈L.P[x]),  length: ||as||,  list: T List,  less_than: a < b,  decidable: Dec(P),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  not: ¬A,  implies: P ⇒ Q,  or: P ∨ Q,  function: x:A ⟶ B[x],  natural_number: $n,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  uimplies: b supposing a,  member: t ∈ T,  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  rev_implies: P ⇐ Q,  or: P ∨ Q,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  false: False,  top: Top,  decidable: Dec(P),  l_all: (∀x∈L.P[x]),  not: ¬A,  int_seg: {i..j-},  guard: {T},  lelt: i ≤ j < k,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  uiff: uiff(P;Q),  subtract: n - m,  ge: i ≥ j ,  le: A ≤ B,  cand: A c∧ B,  true: True,  l_exists: (∃x∈L. P[x]),  select: L[n],  cons: [a / b],  subtype_rel: A ⊆r B
Lemmas referenced :  member-less_than,  length_wf,  l_all_wf,  isect_wf,  not_wf,  equal_wf,  or_wf,  l_member_wf,  l_exists_wf,  all_wf,  decidable_wf,  less_than_wf,  list_wf,  list_induction,  length_of_nil_lemma,  length_of_cons_lemma,  cons_wf,  l_all_cons,  decidable__lt,  select_wf,  int_seg_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,  intformless_wf,  int_formula_prop_less_lemma,  add-member-int_seg2,  subtract_wf,  itermSubtract_wf,  int_term_value_subtract_lemma,  non_neg_length,  itermAdd_wf,  int_term_value_add_lemma,  lelt_wf,  int_seg_wf,  add-associates,  add-swap,  add-commutes,  zero-add,  add-subtract-cancel,  select-cons-tl,  squash_wf,  le_wf,  true_wf,  and_wf,  false_wf,  iff_weakening_equal,  list-cases,  product_subtype_list,  nil_wf,  l_all_nil,  l_exists_iff,  l_all_iff
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  natural_numberEquality,  cumulativity,  hypothesisEquality,  hypothesis,  independent_isectElimination,  rename,  independent_pairFormation,  sqequalRule,  lambdaEquality,  setElimination,  applyEquality,  functionExtensionality,  because_Cache,  setEquality,  functionEquality,  universeEquality,  dependent_functionElimination,  independent_functionElimination,  imageElimination,  productElimination,  voidElimination,  isect_memberEquality,  voidEquality,  addEquality,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  computeAll,  dependent_set_memberEquality,  equalityTransitivity,  equalitySymmetry,  hyp_replacement,  productEquality,  imageMemberEquality,  baseClosed,  instantiate,  applyLambdaEquality,  promote_hyp,  hypothesis_subsumption,  inrFormation,  inlFormation

Latex:
\mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}L:T  List
        (\mforall{}x,y:T.    Dec(x  =  y))
        {}\mRightarrow{}  ((\mforall{}x\mmember{}L.(\mforall{}y\mmember{}L.P[x]  \mvee{}  P[y]  supposing  \mneg{}(x  =  y)))  \mLeftarrow{}{}\mRightarrow{}  (\mexists{}x\mmember{}L.  (\mforall{}y\mmember{}L.P[y]  supposing  \mneg{}(x  =  y)))) 
        supposing  0  <  ||L||



Date html generated: 2017_04_17-AM-07_50_17
Last ObjectModification: 2017_02_27-PM-04_24_43

Theory : list_1


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