Nuprl Lemma : decidable__bag-member2

[T:Type]. ∀x:T. ((∀y:T. Dec(x y ∈ T))  (∀bs:bag(T). Dec(x ↓∈ bs)))


Proof




Definitions occuring in Statement :  bag-member: x ↓∈ bs bag: bag(T) decidable: Dec(P) uall: [x:A]. B[x] all: x:A. B[x] implies:  Q universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] implies:  Q decidable: Dec(P) member: t ∈ T prop: subtype_rel: A ⊆B so_lambda: λ2x.t[x] so_apply: x[s] or: P ∨ Q guard: {T} not: ¬A uimplies: supposing a assert: b ifthenelse: if then else fi  isl: isl(x) btrue: tt true: True bfalse: ff false: False squash: T sq_stable: SqStable(P) exists: x:A. B[x] bag-filter: [x∈b|p[x]] bag-null: bag-null(bs) uiff: uiff(P;Q) and: P ∧ Q iff: ⇐⇒ Q
Lemmas referenced :  decidable__assert bag-null_wf assert_wf isl_wf equal_wf not_wf bag-filter_wf bag_wf all_wf decidable_wf bag-filter-empty or_wf bag-member_wf bag_to_squash_list sq_stable__bag-member list-member-bag-member assert_of_null equal-wf-T-base list_wf filter_wf5 l_member_wf member_exists member_filter and_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation rename cut sqequalHypSubstitution sqequalRule introduction extract_by_obid dependent_functionElimination thin setEquality cumulativity hypothesisEquality isectElimination because_Cache hypothesis applyEquality functionExtensionality lambdaEquality unionElimination universeEquality inrFormation independent_isectElimination independent_functionElimination natural_numberEquality voidElimination equalityTransitivity equalitySymmetry inlFormation imageElimination productElimination promote_hyp hyp_replacement applyLambdaEquality setElimination baseClosed dependent_set_memberEquality independent_pairFormation imageMemberEquality

Latex:
\mforall{}[T:Type].  \mforall{}x:T.  ((\mforall{}y:T.  Dec(x  =  y))  {}\mRightarrow{}  (\mforall{}bs:bag(T).  Dec(x  \mdownarrow{}\mmember{}  bs)))



Date html generated: 2018_05_21-PM-09_46_23
Last ObjectModification: 2017_07_26-PM-06_29_59

Theory : bags_2


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