Nuprl Lemma : Escardo-Xu

¬(∀F:(ℕ ⟶ ℕ) ⟶ ℕ. ∃k:ℕ. ∀g:ℕ ⟶ ℕ((∀i:ℕk. ((g i) 0 ∈ ℕ))  ((F i.0)) (F g) ∈ ℕ)))


Proof




Definitions occuring in Statement :  int_seg: {i..j-} nat: all: x:A. B[x] exists: x:A. B[x] not: ¬A implies:  Q apply: a lambda: λx.A[x] function: x:A ⟶ B[x] natural_number: $n equal: t ∈ T
Definitions unfolded in proof :  lelt: i ≤ j < k int_seg: {i..j-} rev_implies:  Q iff: ⇐⇒ Q true: True top: Top satisfiable_int_formula: satisfiable_int_formula(fmla) decidable: Dec(P) ge: i ≥  squash: T assert: b bnot: ¬bb guard: {T} sq_type: SQType(T) or: P ∨ Q bfalse: ff uimplies: supposing a uiff: uiff(P;Q) ifthenelse: if then else fi  btrue: tt it: unit: Unit bool: 𝔹 pi1: fst(t) subtype_rel: A ⊆B exists: x:A. B[x] false: False less_than': less_than'(a;b) and: P ∧ Q le: A ≤ B all: x:A. B[x] so_apply: x[s] nat: so_lambda: λ2x.t[x] uall: [x:A]. B[x] prop: member: t ∈ T implies:  Q not: ¬A
Lemmas referenced :  decidable__le int_formula_prop_le_lemma intformle_wf ifthenelse_wf assert_of_bnot iff_weakening_uiff iff_transitivity bool_cases not_wf bnot_wf assert_wf int_seg_subtype_nat decidable__lt int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_and_lemma itermVar_wf intformless_wf intformand_wf int_seg_properties iff_weakening_equal int_formula_prop_wf int_term_value_constant_lemma int_formula_prop_eq_lemma int_formula_prop_not_lemma itermConstant_wf intformeq_wf intformnot_wf full-omega-unsat decidable__equal_int nat_properties true_wf squash_wf int_subtype_base set_subtype_base less_than_wf assert-bnot bool_subtype_base subtype_base_sq bool_cases_sqequal eqff_to_assert assert_of_lt_int eqtt_to_assert bool_wf lt_int_wf le_wf false_wf equal_wf equal-wf-T-base int_seg_wf exists_wf nat_wf all_wf
Rules used in proof :  impliesFunctionality int_eqEquality baseClosed imageMemberEquality voidEquality isect_memberEquality approximateComputation applyLambdaEquality levelHypothesis equalityUniverse universeEquality imageElimination intEquality voidElimination cumulativity instantiate independent_isectElimination equalityElimination unionElimination independent_functionElimination dependent_functionElimination equalitySymmetry equalityTransitivity dependent_pairFormation productElimination promote_hyp independent_pairFormation dependent_set_memberEquality hypothesisEquality functionExtensionality applyEquality rename setElimination natural_numberEquality because_Cache lambdaEquality sqequalRule hypothesis functionEquality thin isectElimination sqequalHypSubstitution extract_by_obid introduction cut lambdaFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution

Latex:
\mneg{}(\mforall{}F:(\mBbbN{}  {}\mrightarrow{}  \mBbbN{})  {}\mrightarrow{}  \mBbbN{}.  \mexists{}k:\mBbbN{}.  \mforall{}g:\mBbbN{}  {}\mrightarrow{}  \mBbbN{}.  ((\mforall{}i:\mBbbN{}k.  ((g  i)  =  0))  {}\mRightarrow{}  ((F  (\mlambda{}i.0))  =  (F  g))))



Date html generated: 2017_09_29-PM-06_05_02
Last ObjectModification: 2017_09_22-PM-04_45_41

Theory : fan-theorem


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