Nuprl Lemma : split_tail_max

∀[A:Type]
  ∀f:A ⟶ 𝔹. ∀L:A List. ∀a:A.
    ((a ∈ L) ⇒ ((a ∈ snd(split_tail(L | ∀x.f[x])))) supposing ((∀b:A. (a before b ∈ L ⇒ (↑f[b]))) and (↑f[a])))


Proof




Definitions occuring in Statement :  split_tail: split_tail(L | ∀x.f[x]),  l_before: x before y ∈ l,  l_member: (x ∈ l),  list: T List,  assert: ↑b,  bool: 𝔹,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s],  pi2: snd(t),  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  implies: P ⇒ Q,  prop: ℙ,  uimplies: b supposing a,  so_apply: x[s],  split_tail: split_tail(L | ∀x.f[x]),  so_lambda: so_lambda(x,y,z.t[x; y; z]),  top: Top,  so_apply: x[s1;s2;s3],  pi2: snd(t),  l_member: (x ∈ l),  select: L[n],  nil: [],  it: ⋅,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  cand: A c∧ B,  nat: ℕ,  iff: P ⇐⇒ Q,  and: P ∧ Q,  or: P ∨ Q,  rev_implies: P ⇐ Q,  not: ¬A,  false: False,  bool: 𝔹,  unit: Unit,  btrue: tt,  uiff: uiff(P;Q),  ifthenelse: if b then t else f fi ,  bfalse: ff,  guard: {T}
Lemmas referenced :  list_induction,  all_wf,  l_member_wf,  isect_wf,  assert_wf,  l_before_wf,  split_tail_wf,  list_wf,  pi2_wf,  equal_wf,  list_ind_nil_lemma,  list_ind_cons_lemma,  bool_wf,  length_of_nil_lemma,  stuck-spread,  base_wf,  assert_witness,  nil_wf,  exists_wf,  nat_wf,  less_than_wf,  equal-wf-T-base,  cons_wf,  cons_member,  split_tail_trivial,  cons_before,  bnot_wf,  not_wf,  assert_elim,  not_assert_elim,  and_wf,  btrue_neq_bfalse,  eqtt_to_assert,  uiff_transitivity,  eqff_to_assert,  assert_of_bnot,  list_ind_wf,  ifthenelse_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  lambdaFormation,  cut,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  sqequalRule,  lambdaEquality,  functionEquality,  hypothesis,  applyEquality,  productEquality,  equalityTransitivity,  equalitySymmetry,  dependent_functionElimination,  independent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  rename,  because_Cache,  universeIsType,  universeEquality,  baseClosed,  independent_isectElimination,  functionIsType,  inhabitedIsType,  setElimination,  natural_numberEquality,  productElimination,  unionElimination,  hyp_replacement,  applyLambdaEquality,  inlFormation,  independent_pairFormation,  dependent_set_memberEquality,  equalityElimination,  spreadEquality,  dependent_pairEquality,  inrFormation,  independent_pairEquality

Latex:
\mforall{}[A:Type]
    \mforall{}f:A  {}\mrightarrow{}  \mBbbB{}.  \mforall{}L:A  List.  \mforall{}a:A.
        ((a  \mmember{}  L)
        {}\mRightarrow{}  ((a  \mmember{}  snd(split\_tail(L  |  \mforall{}x.f[x]))))  supposing 
                    ((\mforall{}b:A.  (a  before  b  \mmember{}  L  {}\mRightarrow{}  (\muparrow{}f[b])))  and 
                    (\muparrow{}f[a])))



Date html generated: 2019_10_15-AM-10_54_46
Last ObjectModification: 2018_09_27-AM-10_18_51

Theory : list!


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