Nuprl Lemma : bag-filter-is-empty

[T:Type]. ∀[P:T ⟶ 𝔹]. ∀[b:bag(T)].  uiff(∀x:T. (x ↓∈  (¬↑P[x]));[x∈b|P[x]] {} ∈ bag(T))


Proof




Definitions occuring in Statement :  bag-member: x ↓∈ bs bag-filter: [x∈b|p[x]] empty-bag: {} bag: bag(T) assert: b bool: 𝔹 uiff: uiff(P;Q) uall: [x:A]. B[x] so_apply: x[s] all: x:A. B[x] not: ¬A implies:  Q function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a so_lambda: λ2x.t[x] implies:  Q prop: so_apply: x[s] all: x:A. B[x] not: ¬A false: False subtype_rel: A ⊆B guard: {T} assert: b ifthenelse: if then else fi  bag-null: bag-null(bs) null: null(as) empty-bag: {} nil: [] it: btrue: tt true: True
Lemmas referenced :  bag-filter-empty-iff all_wf bag-member_wf not_wf assert_wf equal-wf-T-base bag_wf bag-filter_wf subtype_rel_bag bool_wf assert-bag-null equal_functionality_wrt_subtype_rel2 bag-null_wf
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation hypothesis sqequalHypSubstitution isectElimination thin hypothesisEquality independent_pairFormation productElimination independent_isectElimination cumulativity sqequalRule lambdaEquality functionEquality applyEquality functionExtensionality dependent_functionElimination voidElimination setEquality setElimination rename because_Cache baseClosed universeEquality equalityTransitivity equalitySymmetry independent_functionElimination natural_numberEquality hyp_replacement Error :applyLambdaEquality

Latex:
\mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[b:bag(T)].    uiff(\mforall{}x:T.  (x  \mdownarrow{}\mmember{}  b  {}\mRightarrow{}  (\mneg{}\muparrow{}P[x]));[x\mmember{}b|P[x]]  =  \{\})



Date html generated: 2016_10_25-AM-10_30_09
Last ObjectModification: 2016_07_12-AM-06_46_11

Theory : bags


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