Nuprl Lemma : mapfilter-reduce

[f:Top]. ∀[T:Type]. ∀[L:T List]. ∀[P:{x:T| (x ∈ L)}  ⟶ 𝔹].
  (mapfilter(f;P;L) reduce(λx,y. if then [f y] else fi ;[];L))


Proof




Definitions occuring in Statement :  mapfilter: mapfilter(f;P;L) l_member: (x ∈ l) reduce: reduce(f;k;as) cons: [a b] nil: [] list: List ifthenelse: if then else fi  bool: 𝔹 uall: [x:A]. B[x] top: Top set: {x:A| B[x]}  apply: a lambda: λx.A[x] function: x:A ⟶ B[x] universe: Type sqequal: t
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T all: x:A. B[x] nat: implies:  Q false: False ge: i ≥  uimplies: supposing a satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] not: ¬A top: Top and: P ∧ Q prop: subtype_rel: A ⊆B guard: {T} or: P ∨ Q mapfilter: mapfilter(f;P;L) 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] so_apply: x[s] sq_type: SQType(T) less_than: a < b squash: T less_than': less_than'(a;b) iff: ⇐⇒ Q rev_implies:  Q bool: 𝔹 unit: Unit btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  bfalse: ff bnot: ¬bb assert: b
Lemmas referenced :  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 l_member_wf bool_wf equal-wf-T-base nat_wf colength_wf_list less_than_transitivity1 less_than_irreflexivity list-cases reduce_nil_lemma filter_nil_lemma map_nil_lemma nil_wf 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 equal_wf subtract_wf itermSubtract_wf int_term_value_subtract_lemma subtype_base_sq set_subtype_base int_subtype_base decidable__equal_int reduce_cons_lemma filter_cons_lemma subtype_rel_dep_function cons_wf subtype_rel_sets cons_member subtype_rel_self set_wf eqtt_to_assert map_cons_lemma eqff_to_assert bool_cases_sqequal bool_subtype_base assert-bnot list_wf top_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut thin lambdaFormation extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality hypothesis setElimination rename intWeakElimination natural_numberEquality independent_isectElimination dependent_pairFormation lambdaEquality int_eqEquality intEquality dependent_functionElimination isect_memberEquality voidElimination voidEquality sqequalRule independent_pairFormation computeAll independent_functionElimination sqequalAxiom functionEquality setEquality cumulativity applyEquality because_Cache unionElimination promote_hyp hypothesis_subsumption productElimination equalityTransitivity equalitySymmetry applyLambdaEquality dependent_set_memberEquality addEquality baseClosed instantiate imageElimination inrFormation functionExtensionality inlFormation equalityElimination universeEquality

Latex:
\mforall{}[f:Top].  \mforall{}[T:Type].  \mforall{}[L:T  List].  \mforall{}[P:\{x:T|  (x  \mmember{}  L)\}    {}\mrightarrow{}  \mBbbB{}].
    (mapfilter(f;P;L)  \msim{}  reduce(\mlambda{}x,y.  if  P  x  then  [f  x  /  y]  else  y  fi  ;[];L))



Date html generated: 2017_04_17-AM-07_25_33
Last ObjectModification: 2017_02_27-PM-04_04_22

Theory : list_1


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