Nuprl Lemma : lsum-of-even

∀[T:Type]. ∀[L:T List]. ∀[f:{x:T| (x ∈ L)}  ⟶ ℤ].  ↑isEven(Σ(f[x] | x ∈ L)) supposing (∀x∈L.↑isEven(f[x]))


Proof




Definitions occuring in Statement :  isEven: isEven(n),  lsum: Σ(f[x] | x ∈ L),  l_all: (∀x∈L.P[x]),  l_member: (x ∈ l),  list: T List,  assert: ↑b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s],  set: {x:A| B[x]} ,  function: x:A ⟶ B[x],  int: ℤ,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  all: ∀x:A. B[x],  nat: ℕ,  implies: P ⇒ Q,  false: False,  ge: i ≥ j ,  uimplies: b supposing a,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  and: P ∧ Q,  prop: ℙ,  guard: {T},  or: P ∨ Q,  so_lambda: λ2x.t[x],  so_apply: x[s],  assert: ↑b,  ifthenelse: if b then t else f fi ,  isEven: isEven(n),  eq_int: (i =z j),  modulus: a mod n,  remainder: n rem m,  btrue: tt,  true: True,  subtype_rel: A ⊆r B,  cons: [a / b],  le: A ≤ B,  less_than': less_than'(a;b),  colength: colength(L),  nil: [],  it: ⋅,  sq_type: SQType(T),  less_than: a < b,  squash: ↓T,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  decidable: Dec(P),  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  l_member: (x ∈ l),  select: L[n],  cand: A c∧ B,  nat_plus: ℕ+,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  same-parity: same-parity(n;m),  bool: 𝔹,  unit: Unit,  bfalse: ff,  bnot: ¬bb
Lemmas referenced :  nat_properties,  full-omega-unsat,  intformand_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  intformless_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  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,  istype-less_than,  assert_witness,  intformeq_wf,  int_formula_prop_eq_lemma,  list-cases,  lsum_nil_lemma,  isEven_wf,  l_all_wf_nil,  assert_wf,  l_member_wf,  nil_wf,  product_subtype_list,  colength-cons-not-zero,  colength_wf_list,  istype-le,  lsum_wf,  subtract-1-ge-0,  subtype_base_sq,  set_subtype_base,  int_subtype_base,  spread_cons_lemma,  decidable__equal_int,  subtract_wf,  intformnot_wf,  itermSubtract_wf,  itermAdd_wf,  int_formula_prop_not_lemma,  int_term_value_subtract_lemma,  int_term_value_add_lemma,  decidable__le,  le_wf,  lsum_cons_lemma,  subtype_rel_dep_function,  cons_wf,  subtype_rel_sets_simple,  cons_member,  l_all_cons,  length_of_cons_lemma,  add_nat_plus,  length_wf_nat,  decidable__lt,  nat_plus_properties,  add-is-int-iff,  false_wf,  length_wf,  select_wf,  list-subtype,  subtype_rel_list,  subtype_rel_sets,  l_all_wf,  istype-nat,  list_wf,  istype-universe,  isEven-add,  eqtt_to_assert,  eqff_to_assert,  bool_cases_sqequal,  bool_wf,  bool_subtype_base
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  thin,  lambdaFormation_alt,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  hypothesis,  setElimination,  rename,  intWeakElimination,  natural_numberEquality,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation_alt,  lambdaEquality_alt,  int_eqEquality,  dependent_functionElimination,  isect_memberEquality_alt,  voidElimination,  sqequalRule,  independent_pairFormation,  universeIsType,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  isectIsTypeImplies,  inhabitedIsType,  functionIsTypeImplies,  unionElimination,  applyEquality,  dependent_set_memberEquality_alt,  because_Cache,  functionIsType,  setIsType,  promote_hyp,  hypothesis_subsumption,  productElimination,  equalityIstype,  instantiate,  imageElimination,  baseApply,  closedConclusion,  baseClosed,  intEquality,  sqequalBase,  setEquality,  inrFormation_alt,  pointwiseFunctionality,  productIsType,  addEquality,  universeEquality,  equalityElimination,  cumulativity

Latex:
\mforall{}[T:Type].  \mforall{}[L:T  List].  \mforall{}[f:\{x:T|  (x  \mmember{}  L)\}    {}\mrightarrow{}  \mBbbZ{}].
    \muparrow{}isEven(\mSigma{}(f[x]  |  x  \mmember{}  L))  supposing  (\mforall{}x\mmember{}L.\muparrow{}isEven(f[x]))



Date html generated: 2020_05_19-PM-10_01_34
Last ObjectModification: 2019_11_13-AM-10_10_24

Theory : num_thy_1


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