Nuprl Lemma : filter-length-less

∀[T:Type]. ∀[P:T ⟶ 𝔹]. ∀[L:T List].  ||filter(λx.P[x];L)|| < ||L|| supposing ∃x:T. ((x ∈ L) ∧ (¬↑P[x]))


Proof




Definitions occuring in Statement :  l_member: (x ∈ l),  length: ||as||,  filter: filter(P;l),  list: T List,  assert: ↑b,  bool: 𝔹,  less_than: a < b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s],  exists: ∃x:A. B[x],  not: ¬A,  and: P ∧ Q,  lambda: λx.A[x],  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  exists: ∃x:A. B[x],  and: P ∧ Q,  all: ∀x:A. B[x],  so_apply: x[s],  prop: ℙ,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  cand: A c∧ B,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  decidable: Dec(P),  or: P ∨ Q,  less_than: a < b,  squash: ↓T,  false: False,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  top: Top
Lemmas referenced :  filter-split-length,  member_filter_2,  bnot_wf,  l_member_wf,  assert_of_bnot,  l_member_length,  filter_wf5,  decidable__lt,  length_wf,  add-is-int-iff,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformless_wf,  itermVar_wf,  itermConstant_wf,  intformeq_wf,  itermAdd_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_eq_lemma,  int_term_value_add_lemma,  int_formula_prop_wf,  false_wf,  istype-assert,  list_wf,  bool_wf,  istype-universe
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  productElimination,  dependent_functionElimination,  lambdaEquality_alt,  applyEquality,  setElimination,  rename,  setIsType,  inhabitedIsType,  universeIsType,  independent_functionElimination,  sqequalRule,  independent_pairFormation,  independent_isectElimination,  equalityTransitivity,  equalitySymmetry,  unionElimination,  imageElimination,  pointwiseFunctionality,  promote_hyp,  baseApply,  closedConclusion,  baseClosed,  natural_numberEquality,  approximateComputation,  dependent_pairFormation_alt,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  productIsType,  functionIsType,  instantiate,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[L:T  List].
    ||filter(\mlambda{}x.P[x];L)||  <  ||L||  supposing  \mexists{}x:T.  ((x  \mmember{}  L)  \mwedge{}  (\mneg{}\muparrow{}P[x]))



Date html generated: 2020_05_19-PM-09_42_47
Last ObjectModification: 2019_10_29-AM-10_00_34

Theory : list_1


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