Nuprl Lemma : filter_iseg2

∀[T:Type]. ∀L2,L1:T List. ∀P:{x:T| (x ∈ L2)}  ⟶ 𝔹.  (L1 ≤ L2 ⇒ filter(P;L1) ≤ filter(P;L2))


Proof




Definitions occuring in Statement :  iseg: l1 ≤ l2,  l_member: (x ∈ l),  filter: filter(P;l),  list: T List,  bool: 𝔹,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  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],  prop: ℙ,  implies: P ⇒ Q,  subtype_rel: A ⊆r B,  so_apply: x[s],  uimplies: b supposing a,  istype: istype(T),  top: Top,  iff: P ⇐⇒ Q,  and: P ∧ Q,  uiff: uiff(P;Q),  rev_implies: P ⇐ Q,  or: P ∨ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  ifthenelse: if b then t else f fi ,  cons: [a / b],  bfalse: ff,  exists: ∃x:A. B[x],  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  false: False,  cand: A c∧ B,  squash: ↓T,  not: ¬A
Lemmas referenced :  list_induction,  list_wf,  l_member_wf,  bool_wf,  iseg_wf,  filter_wf5,  subtype_rel_dep_function,  subtype_rel_sets_simple,  iseg_member,  filter_nil_lemma,  istype-void,  nil_wf,  filter_cons_lemma,  cons_wf,  istype-universe,  iseg_nil,  assert_of_null,  sqequal-nil,  nil_iseg,  cons_member,  eqtt_to_assert,  list-cases,  product_subtype_list,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  cons_iseg,  equal_wf,  assert_elim,  bfalse_wf,  bnot_wf,  btrue_neq_bfalse,  not_assert_elim
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  Error :lambdaFormation_alt,  cut,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  sqequalRule,  Error :lambdaEquality_alt,  functionEquality,  hypothesis,  setEquality,  applyEquality,  Error :setIsType,  Error :universeIsType,  because_Cache,  independent_isectElimination,  dependent_functionElimination,  independent_functionElimination,  Error :isect_memberEquality_alt,  voidElimination,  Error :functionIsType,  rename,  Error :inhabitedIsType,  instantiate,  universeEquality,  productElimination,  equalityTransitivity,  equalitySymmetry,  Error :inlFormation_alt,  Error :dependent_set_memberEquality_alt,  unionElimination,  equalityElimination,  Error :inrFormation_alt,  Error :equalityIstype,  promote_hyp,  hypothesis_subsumption,  Error :dependent_pairFormation_alt,  cumulativity,  hyp_replacement,  applyLambdaEquality,  independent_pairFormation,  setElimination,  imageMemberEquality,  baseClosed,  imageElimination,  Error :productIsType

Latex:
\mforall{}[T:Type].  \mforall{}L2,L1:T  List.  \mforall{}P:\{x:T|  (x  \mmember{}  L2)\}    {}\mrightarrow{}  \mBbbB{}.    (L1  \mleq{}  L2  {}\mRightarrow{}  filter(P;L1)  \mleq{}  filter(P;L2))



Date html generated: 2019_06_20-PM-01_29_10
Last ObjectModification: 2019_01_17-PM-04_24_47

Theory : list_1


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