Nuprl Lemma : fset-constrained-ac-glb-is-glb

∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[P:fset(T) ⟶ 𝔹].
  ∀[ac1,ac2:{ac:fset(fset(T))| (↑fset-antichain(eq;ac)) ∧ fset-all(ac;a.P[a])} ].
    greatest-lower-bound({ac:fset(fset(T))| 
                          (↑fset-antichain(eq;ac)) ∧ fset-all(ac;a.P[a])} ;ac1,ac2.fset-ac-le(eq;ac1;ac2);ac1;ac2;glb(P;\000Cac1;ac2)) 
  supposing ∀x,y:fset(T).  (y ⊆ x ⇒ (↑(P x)) ⇒ (↑(P y)))


Proof




Definitions occuring in Statement :  fset-constrained-ac-glb: glb(P;ac1;ac2),  fset-ac-le: fset-ac-le(eq;ac1;ac2),  fset-antichain: fset-antichain(eq;ac),  fset-all: fset-all(s;x.P[x]),  f-subset: xs ⊆ ys,  fset: fset(T),  deq: EqDecider(T),  greatest-lower-bound: greatest-lower-bound(T;x,y.R[x; y];a;b;c),  assert: ↑b,  bool: 𝔹,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  set: {x:A| B[x]} ,  apply: f a,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  greatest-lower-bound: greatest-lower-bound(T;x,y.R[x; y];a;b;c),  and: P ∧ Q,  cand: A c∧ B,  all: ∀x:A. B[x],  implies: P ⇒ Q,  prop: ℙ,  fset-ac-le: fset-ac-le(eq;ac1;ac2),  fset-all: fset-all(s;x.P[x]),  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  so_apply: x[s],  fset-constrained-ac-glb: glb(P;ac1;ac2),  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  not: ¬A,  squash: ↓T,  false: False,  exists: ∃x:A. B[x],  guard: {T},  top: Top,  true: True,  sq_stable: SqStable(P)
Lemmas referenced :  fset-ac-le_wf,  assert_witness,  fset-null_wf,  fset_wf,  fset-filter_wf,  bnot_wf,  deq-f-subset_wf,  fset-constrained-ac-glb_wf,  assert_wf,  fset-antichain_wf,  fset-all_wf,  set_wf,  all_wf,  f-subset_wf,  bool_wf,  deq_wf,  fset-all-iff,  deq-fset_wf,  iff_weakening_uiff,  fset-minimals_wf,  f-proper-subset-dec_wf,  f-union_wf,  fset-constrained-image_wf,  fset-union_wf,  uall_wf,  isect_wf,  fset-member_wf,  assert_of_bnot,  iff_wf,  member-fset-minimals,  assert-fset-null,  not_wf,  equal-wf-T-base,  member-f-union,  member-fset-constrained-image-iff,  member-fset-filter,  assert-deq-f-subset,  f-subset-union,  mem_empty_lemma,  squash_wf,  true_wf,  fset-union-commutes,  iff_weakening_equal,  fset-ac-le_transitivity,  fset-minimals-ac-le,  fset-ac-le-implies2,  f-union-subset,  equal_wf,  sq_stable_from_decidable,  decidable__assert
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  independent_pairFormation,  hypothesis,  lambdaFormation,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  cumulativity,  hypothesisEquality,  setElimination,  rename,  because_Cache,  sqequalRule,  productElimination,  independent_pairEquality,  lambdaEquality,  applyEquality,  functionExtensionality,  setEquality,  productEquality,  independent_functionElimination,  dependent_functionElimination,  isect_memberEquality,  functionEquality,  equalityTransitivity,  equalitySymmetry,  universeEquality,  independent_isectElimination,  addLevel,  impliesFunctionality,  baseClosed,  imageElimination,  hyp_replacement,  applyLambdaEquality,  voidElimination,  voidEquality,  natural_numberEquality,  imageMemberEquality,  dependent_pairFormation

Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[P:fset(T)  {}\mrightarrow{}  \mBbbB{}].
    \mforall{}[ac1,ac2:\{ac:fset(fset(T))|  (\muparrow{}fset-antichain(eq;ac))  \mwedge{}  fset-all(ac;a.P[a])\}  ].
        greatest-lower-bound(\{ac:fset(fset(T))| 
                                                    (\muparrow{}fset-antichain(eq;ac))  \mwedge{}  fset-all(ac;a.P[a])\}  ;ac1,ac2.fset-ac-le(eq;ac1\000C;ac2);ac1;ac2;...) 
    supposing  \mforall{}x,y:fset(T).    (y  \msubseteq{}  x  {}\mRightarrow{}  (\muparrow{}(P  x))  {}\mRightarrow{}  (\muparrow{}(P  y)))



Date html generated: 2017_04_17-AM-09_25_00
Last ObjectModification: 2017_02_27-PM-05_27_11

Theory : finite!sets


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