Nuprl Lemma : simple_fan_theorem

[X:n:ℕ ⟶ (ℕn ⟶ 𝔹) ⟶ ℙ]
  (∀n:ℕ. ∀s:ℕn ⟶ 𝔹.  Dec(X[n;s]))  (∃k:ℕ [(∀f:ℕ ⟶ 𝔹. ∃n:ℕk. X[n;f])]) supposing ∀f:ℕ ⟶ 𝔹(↓∃n:ℕX[n;f])


Proof




Definitions occuring in Statement :  int_seg: {i..j-} nat: bool: 𝔹 decidable: Dec(P) uimplies: supposing a uall: [x:A]. B[x] prop: so_apply: x[s1;s2] all: x:A. B[x] sq_exists: x:A [B[x]] exists: x:A. B[x] squash: T implies:  Q function: x:A ⟶ B[x] natural_number: $n
Definitions unfolded in proof :  uall: [x:A]. B[x] uimplies: supposing a member: t ∈ T all: x:A. B[x] squash: T implies:  Q so_lambda: λ2y.t[x; y] so_lambda: λ2x.t[x] nat: so_apply: x[s1;s2] int_seg: {i..j-} guard: {T} sq_stable: SqStable(P) lelt: i ≤ j < k and: P ∧ Q prop: subtype_rel: A ⊆B le: A ≤ B less_than': less_than'(a;b) false: False not: ¬A so_apply: x[s] decidable: Dec(P) or: P ∨ Q iff: ⇐⇒ Q rev_implies:  Q uiff: uiff(P;Q) subtract: m top: Top true: True sq_exists: x:A [B[x]] exists: x:A. B[x] less_than: a < b seq-append: seq-append(n;m;s1;s2) bool: 𝔹 unit: Unit it: btrue: tt bfalse: ff sq_type: SQType(T) bnot: ¬bb ifthenelse: if then else fi  assert: b ge: i ≥  nat_plus: + seq-adjoin: s++t
Lemmas referenced :  nat_wf bool_wf basic_bar_induction sq_exists_wf all_wf exists_wf int_seg_wf add_nat_wf sq_stable__le equal_wf le_wf seq-append_wf int_seg_subtype_nat false_wf subtype_rel_function subtype_rel_self decidable__le not-le-2 condition-implies-le minus-add minus-one-mul zero-add minus-one-mul-top add-associates add-swap add-commutes add_functionality_wrt_le add-zero le-add-cancel seq-adjoin_wf decidable_wf squash_wf and_wf less_than_wf lt_int_wf eqtt_to_assert assert_of_lt_int top_wf eqff_to_assert bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot not-lt-2 less-iff-le btrue_wf set_wf set-value-type int-value-type bfalse_wf add-member-int_seg2 subtract_wf le-add-cancel2 decidable__lt minus-minus sq_stable__and sq_stable__less_than member-less_than le_reflexive one-mul add-mul-special two-mul mul-distributes-right zero-mul minus-zero omega-shadow mul-distributes mul-commutes mul-associates mul-swap nat_properties int_subtype_base iff_imp_equal_bool assert_wf true_wf not-less-implies-equal le-add-cancel-alt set_subtype_base decidable__int_equal not-equal-2 less_than_transitivity1 less_than_irreflexivity
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation cut introduction sqequalRule sqequalHypSubstitution lambdaEquality dependent_functionElimination thin hypothesisEquality imageElimination hypothesis imageMemberEquality baseClosed functionEquality extract_by_obid rename lambdaFormation isectElimination because_Cache natural_numberEquality setElimination applyEquality functionExtensionality dependent_set_memberEquality addEquality independent_functionElimination productElimination equalityTransitivity equalitySymmetry independent_isectElimination independent_pairFormation unionElimination voidElimination isect_memberEquality voidEquality intEquality minusEquality cumulativity universeEquality dependent_set_memberFormation dependent_pairFormation addLevel hyp_replacement levelHypothesis equalityElimination lessCases axiomSqEquality promote_hyp instantiate cutEval multiplyEquality

Latex:
\mforall{}[X:n:\mBbbN{}  {}\mrightarrow{}  (\mBbbN{}n  {}\mrightarrow{}  \mBbbB{})  {}\mrightarrow{}  \mBbbP{}]
    (\mforall{}n:\mBbbN{}.  \mforall{}s:\mBbbN{}n  {}\mrightarrow{}  \mBbbB{}.    Dec(X[n;s]))  {}\mRightarrow{}  (\mexists{}k:\mBbbN{}  [(\mforall{}f:\mBbbN{}  {}\mrightarrow{}  \mBbbB{}.  \mexists{}n:\mBbbN{}k.  X[n;f])]) 
    supposing  \mforall{}f:\mBbbN{}  {}\mrightarrow{}  \mBbbB{}.  (\mdownarrow{}\mexists{}n:\mBbbN{}.  X[n;f])



Date html generated: 2019_06_20-AM-11_32_31
Last ObjectModification: 2018_08_20-PM-09_32_25

Theory : bool_1


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