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 ⊆  (↑(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: supposing a uall: [x:A]. B[x] so_apply: x[s] all: x:A. B[x] implies:  Q and: P ∧ Q set: {x:A| B[x]}  apply: a function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a greatest-lower-bound: greatest-lower-bound(T;x,y.R[x; y];a;b;c) and: P ∧ Q cand: c∧ B all: x:A. B[x] implies:  Q prop: 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 ⊆B so_apply: x[s] fset-constrained-ac-glb: glb(P;ac1;ac2) so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] iff: ⇐⇒ Q rev_implies:  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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