Nuprl Lemma : remove-repeats-mapfilter-with-fun

∀[T,U:Type]. ∀[eq:EqDecider(U)]. ∀[R:T ⟶ T ⟶ 𝔹]. ∀[L:T List]. ∀[P:T ⟶ 𝔹]. ∀[f:{x:T| ↑(P x)}  ⟶ U].
  (remove-repeats(eq;mapfilter(f;P;L))
     = mapfilter(f;λa.((P a) ∧b (¬b(∃x∈L.(P x) ∧b R[x;a] ∧b (eq (f x) (f a)))_b));L)
     ∈ (U List)) supposing 
     (sorted-by(λx,y. (↑R[x;y]);L) and 
     StAntiSym(T;x,y.↑R[x;y]) and 
     Irrefl(T;x,y.↑R[x;y]))


Proof




Definitions occuring in Statement :  remove-repeats: remove-repeats(eq;L),  bl-exists: (∃x∈L.P[x])_b,  sorted-by: sorted-by(R;L),  mapfilter: mapfilter(f;P;L),  list: T List,  deq: EqDecider(T),  irrefl: Irrefl(T;x,y.E[x; y]),  st_anti_sym: StAntiSym(T;x,y.R[x; y]),  band: p ∧b q,  bnot: ¬bb,  assert: ↑b,  bool: 𝔹,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s1;s2],  set: {x:A| B[x]} ,  apply: f a,  lambda: λx.A[x],  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  mapfilter: mapfilter(f;P;L),  squash: ↓T,  prop: ℙ,  subtype_rel: A ⊆r B,  so_lambda: λ2x.t[x],  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  band: p ∧b q,  ifthenelse: if b then t else f fi ,  uiff: uiff(P;Q),  and: P ∧ Q,  so_apply: x[s1;s2],  deq: EqDecider(T),  bfalse: ff,  or: P ∨ Q,  assert: ↑b,  true: True,  false: False,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  so_lambda: λ2x y.t[x; y],  irrefl: Irrefl(T;x,y.E[x; y]),  st_anti_sym: StAntiSym(T;x,y.R[x; y]),  top: Top
Lemmas referenced :  equal_wf,  squash_wf,  true_wf,  list_wf,  remove-repeats-fun-map2,  filter_wf5,  subtype_rel_dep_function,  bool_wf,  l_member_wf,  subtype_rel_self,  set_wf,  map_wf,  assert_wf,  eqtt_to_assert,  bnot_wf,  bl-exists_wf,  subtype_rel_sets,  bool_cases_sqequal,  filter_type,  iff_weakening_equal,  sorted-by_wf,  st_anti_sym_wf,  irrefl_wf,  deq_wf,  member_filter_2,  remove-repeats-fun-as-filter,  sorted-by-filter,  filter-filter,  bl-exists-filter,  mapfilter_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  applyEquality,  thin,  lambdaEquality,  sqequalHypSubstitution,  imageElimination,  extract_by_obid,  isectElimination,  hypothesisEquality,  equalityTransitivity,  hypothesis,  equalitySymmetry,  because_Cache,  cumulativity,  sqequalRule,  setEquality,  independent_isectElimination,  setElimination,  rename,  lambdaFormation,  unionElimination,  equalityElimination,  productElimination,  functionExtensionality,  dependent_set_memberEquality,  dependent_functionElimination,  independent_functionElimination,  natural_numberEquality,  voidElimination,  imageMemberEquality,  baseClosed,  universeEquality,  isect_memberEquality,  axiomEquality,  functionEquality,  voidEquality

Latex:
\mforall{}[T,U:Type].  \mforall{}[eq:EqDecider(U)].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[L:T  List].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].
\mforall{}[f:\{x:T|  \muparrow{}(P  x)\}    {}\mrightarrow{}  U].
    (remove-repeats(eq;mapfilter(f;P;L))
          =  mapfilter(f;\mlambda{}a.((P  a)  \mwedge{}\msubb{}  (\mneg{}\msubb{}(\mexists{}x\mmember{}L.(P  x)  \mwedge{}\msubb{}  R[x;a]  \mwedge{}\msubb{}  (eq  (f  x)  (f  a)))\_b));L))  supposing 
          (sorted-by(\mlambda{}x,y.  (\muparrow{}R[x;y]);L)  and 
          StAntiSym(T;x,y.\muparrow{}R[x;y])  and 
          Irrefl(T;x,y.\muparrow{}R[x;y]))



Date html generated: 2017_04_17-AM-09_12_38
Last ObjectModification: 2017_02_27-PM-05_20_00

Theory : decidable!equality


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