Nuprl Lemma : bag-bind-filter

[A,B:Type]. ∀[p:A ⟶ 𝔹]. ∀[f:{a:A| ↑p[a]}  ⟶ bag(B)]. ∀[ba:bag(A)].
  (bag-bind([a∈ba|p[a]];λa.f[a]) bag-bind(ba;λa.if p[a] then f[a] else {} fi ) ∈ bag(B))


Proof




Definitions occuring in Statement :  bag-bind: bag-bind(bs;f) bag-filter: [x∈b|p[x]] empty-bag: {} bag: bag(T) assert: b ifthenelse: if then else fi  bool: 𝔹 uall: [x:A]. B[x] so_apply: x[s] set: {x:A| B[x]}  lambda: λx.A[x] function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T bag-bind: bag-bind(bs;f) bag: bag(T) quotient: x,y:A//B[x; y] and: P ∧ Q all: x:A. B[x] implies:  Q prop: so_apply: x[s] empty-bag: {} bag-map: bag-map(f;bs) bag-union: bag-union(bbs) bag-filter: [x∈b|p[x]] concat: concat(ll) nat: false: False ge: i ≥  uimplies: supposing a satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] not: ¬A top: Top subtype_rel: A ⊆B guard: {T} or: P ∨ Q cons: [a b] colength: colength(L) so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] decidable: Dec(P) nil: [] it: so_lambda: λ2x.t[x] sq_type: SQType(T) less_than: a < b squash: T less_than': less_than'(a;b) bool: 𝔹 unit: Unit btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  bfalse: ff bnot: ¬bb assert: b append: as bs so_lambda: so_lambda(x,y,z.t[x; y; z]) so_apply: x[s1;s2;s3] bag-append: as bs true: True iff: ⇐⇒ Q rev_implies:  Q
Lemmas referenced :  bag_wf list_wf permutation_wf equal_wf equal-wf-base assert_wf bool_wf nat_properties satisfiable-full-omega-tt intformand_wf intformle_wf itermConstant_wf itermVar_wf intformless_wf int_formula_prop_and_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_wf ge_wf less_than_wf equal-wf-T-base nat_wf colength_wf_list less_than_transitivity1 less_than_irreflexivity list-cases filter_nil_lemma map_nil_lemma reduce_nil_lemma product_subtype_list spread_cons_lemma intformeq_wf itermAdd_wf int_formula_prop_eq_lemma int_term_value_add_lemma decidable__le intformnot_wf int_formula_prop_not_lemma le_wf subtract_wf itermSubtract_wf int_term_value_subtract_lemma subtype_base_sq set_subtype_base int_subtype_base decidable__equal_int filter_cons_lemma map_cons_lemma reduce_cons_lemma empty-bag_wf eqtt_to_assert eqff_to_assert bool_cases_sqequal bool_subtype_base assert-bnot list_ind_nil_lemma squash_wf true_wf bag-append_wf iff_weakening_equal quotient-member-eq permutation-equiv bag-union_wf bag-map_wf list-subtype-bag
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalHypSubstitution pointwiseFunctionalityForEquality extract_by_obid isectElimination thin cumulativity hypothesisEquality hypothesis sqequalRule pertypeElimination productElimination equalityTransitivity equalitySymmetry lambdaFormation because_Cache rename dependent_functionElimination independent_functionElimination productEquality isect_memberEquality axiomEquality functionEquality setEquality applyEquality functionExtensionality hyp_replacement applyLambdaEquality setElimination intWeakElimination natural_numberEquality independent_isectElimination dependent_pairFormation lambdaEquality int_eqEquality intEquality voidElimination voidEquality independent_pairFormation computeAll unionElimination promote_hyp hypothesis_subsumption dependent_set_memberEquality addEquality baseClosed instantiate imageElimination equalityElimination universeEquality imageMemberEquality

Latex:
\mforall{}[A,B:Type].  \mforall{}[p:A  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[f:\{a:A|  \muparrow{}p[a]\}    {}\mrightarrow{}  bag(B)].  \mforall{}[ba:bag(A)].
    (bag-bind([a\mmember{}ba|p[a]];\mlambda{}a.f[a])  =  bag-bind(ba;\mlambda{}a.if  p[a]  then  f[a]  else  \{\}  fi  ))



Date html generated: 2017_10_01-AM-09_06_19
Last ObjectModification: 2017_07_26-PM-04_46_27

Theory : bags


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