Nuprl Lemma : length-filter-lower-bound

∀[A:Type]. ∀[P:A ⟶ 𝔹]. ∀[L:A List]. ∀[T:Type]. ∀[k:ℕ]. ∀[f:{i:ℕ||L||| ¬↑P[L[i]]}  ⟶ T].
  ((||L|| - k) ≤ ||filter(P;L)||) supposing (T ~ ℕk and Inj({i:ℕ||L||| ¬↑P[L[i]]} ;T;f))


Proof




Definitions occuring in Statement :  equipollent: A ~ B,  select: L[n],  length: ||as||,  filter: filter(P;l),  list: T List,  inject: Inj(A;B;f),  int_seg: {i..j-},  nat: ℕ,  assert: ↑b,  bool: 𝔹,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s],  le: A ≤ B,  not: ¬A,  set: {x:A| B[x]} ,  function: x:A ⟶ B[x],  subtract: n - m,  natural_number: $n,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  le: A ≤ B,  and: P ∧ Q,  nat: ℕ,  so_apply: x[s],  int_seg: {i..j-},  guard: {T},  ge: i ≥ j ,  lelt: i ≤ j < k,  all: ∀x:A. B[x],  decidable: Dec(P),  or: P ∨ Q,  not: ¬A,  implies: P ⇒ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  top: Top,  prop: ℙ,  less_than: a < b,  squash: ↓T,  so_lambda: λ2x.t[x],  cand: A c∧ B,  biject: Bij(A;B;f),  equipollent: A ~ B,  sq_stable: SqStable(P),  subtype_rel: A ⊆r B,  ext-eq: A ≡ B,  istype: istype(T),  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  inject: Inj(A;B;f),  uiff: uiff(P;Q)
Lemmas referenced :  le_witness_for_triv,  equipollent_wf,  int_seg_wf,  inject_wf,  length_wf,  not_wf,  assert_wf,  select_wf,  int_seg_properties,  nat_properties,  decidable__le,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma,  istype-universe,  nat_wf,  list_wf,  bool_wf,  equipollent-partition,  length_wf_nat,  equipollent_same,  decidable__assert,  equipollent-subtract2,  filter_wf5,  subtype_rel_dep_function,  l_member_wf,  subtract_wf,  equipollent_functionality_wrt_equipollent,  equipollent_weakening_ext-eq,  ext-eq_weakening,  equipollent-nsub,  equipollent_inversion,  pigeon-hole,  itermSubtract_wf,  int_term_value_subtract_lemma,  le_wf,  subtract-is-int-iff,  intformeq_wf,  int_formula_prop_eq_lemma,  false_wf,  equipollent_transitivity,  subtype_rel_self,  set_wf,  sq_stable__not,  subtype_rel_sets,  equipollent-filter,  compose_wf,  injection-composition,  satisfiable-full-omega-tt
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  productElimination,  equalityTransitivity,  hypothesis,  equalitySymmetry,  independent_isectElimination,  Error :universeIsType,  hypothesisEquality,  natural_numberEquality,  setElimination,  rename,  sqequalRule,  Error :isect_memberEquality_alt,  because_Cache,  setEquality,  cumulativity,  applyEquality,  functionExtensionality,  dependent_functionElimination,  unionElimination,  approximateComputation,  independent_functionElimination,  Error :dependent_pairFormation_alt,  Error :lambdaEquality_alt,  int_eqEquality,  voidElimination,  independent_pairFormation,  imageElimination,  Error :functionIsType,  Error :setIsType,  Error :inhabitedIsType,  universeEquality,  Error :lambdaFormation_alt,  computeAll,  voidEquality,  isect_memberEquality,  intEquality,  lambdaEquality,  lemma_by_obid,  productEquality,  dependent_pairFormation,  functionEquality,  lambdaFormation,  baseClosed,  imageMemberEquality,  dependent_set_memberEquality,  promote_hyp,  Error :dependent_set_memberEquality_alt,  applyLambdaEquality,  Error :equalityIsType1,  pointwiseFunctionality,  baseApply,  closedConclusion

Latex:
\mforall{}[A:Type].  \mforall{}[P:A  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[L:A  List].  \mforall{}[T:Type].  \mforall{}[k:\mBbbN{}].  \mforall{}[f:\{i:\mBbbN{}||L|||  \mneg{}\muparrow{}P[L[i]]\}    {}\mrightarrow{}  T].
    ((||L||  -  k)  \mleq{}  ||filter(P;L)||)  supposing  (T  \msim{}  \mBbbN{}k  and  Inj(\{i:\mBbbN{}||L|||  \mneg{}\muparrow{}P[L[i]]\}  ;T;f))



Date html generated: 2019_06_20-PM-02_19_48
Last ObjectModification: 2018_10_05-PM-04_11_09

Theory : equipollence!!cardinality!


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