Nuprl Lemma : implies-sum-of-two-squares

∀n:ℕ. ((∃x:ℤ-o. ∃w,y:ℤ. ((n * x * x) = ((w * w) + (y * y)) ∈ ℤ)) ⇒ (∃a,b:ℤ. (n = ((a * a) + (b * b)) ∈ ℤ)))


Proof




Definitions occuring in Statement :  int_nzero: ℤ-o,  nat: ℕ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  multiply: n * m,  add: n + m,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x],  member: t ∈ T,  int_seg: {i..j-},  lelt: i ≤ j < k,  and: P ∧ Q,  le: A ≤ B,  uimplies: b supposing a,  not: ¬A,  implies: P ⇒ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  top: Top,  prop: ℙ,  decidable: Dec(P),  or: P ∨ Q,  subtype_rel: A ⊆r B,  so_lambda: λ2x.t[x],  so_apply: x[s],  guard: {T},  sq_type: SQType(T),  nat: ℕ,  ge: i ≥ j ,  nat_plus: ℕ+,  cand: A c∧ B,  less_than: a < b,  squash: ↓T,  divides: b | a,  Prime: Prime,  int_upper: {i...},  sq_stable: SqStable(P),  less_than': less_than'(a;b),  int_nzero: ℤ-o,  nequal: a ≠ b ∈ T ,  gt: i > j,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  eqmod: a ≡ b mod m,  prime: prime(a),  true: True,  sq_exists: ∃x:A [B[x]],  mul-list: Π(ns) ,  reduce: reduce(f;k;as),  list_ind: list_ind,  cons: [a / b],  l_member: (x ∈ l),  select: L[n],  uiff: uiff(P;Q),  assert: ↑b,  ifthenelse: if b then t else f fi ,  bnot: ¬bb,  bfalse: ff,  btrue: tt,  it: ⋅,  unit: Unit,  bool: 𝔹
Lemmas referenced :  int_seg_properties,  full-omega-unsat,  intformand_wf,  intformless_wf,  itermVar_wf,  itermConstant_wf,  intformle_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_wf,  int_seg_wf,  decidable__equal_int,  subtract_wf,  subtype_base_sq,  set_subtype_base,  int_subtype_base,  intformnot_wf,  intformeq_wf,  itermSubtract_wf,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_subtract_lemma,  decidable__le,  decidable__lt,  istype-le,  istype-less_than,  subtype_rel_self,  nat_properties,  lelt_wf,  decidable__exists-divisor,  le_wf,  divides_wf,  decidable__cand,  decidable__divides_ext,  less_than_wf,  equal-wf-base,  primrec-wf2,  itermAdd_wf,  int_term_value_add_lemma,  nat_wf,  istype-nat,  itermMultiply_wf,  int_term_value_mul_lemma,  mul_preserves_le,  multiply_nat_wf,  mul_bounds_1b,  subtype_rel_sets,  prime_wf,  sq_stable__le,  sq_stable_from_decidable,  decidable__prime,  upper_subtype_nat,  istype-false,  int_upper_properties,  Prime_wf,  mul_cancel_in_eq,  mul_nzero,  nequal_wf,  pos_mul_arg_bounds,  mul_preserves_lt,  prime-sum-of-two-squares,  eqmod_wf,  int_upper_wf,  istype-int_upper,  prime_divs_prod,  equal_wf,  squash_wf,  true_wf,  istype-universe,  iff_weakening_equal,  mul-associates,  prime-factors,  sq_stable__equal,  l_member_wf,  list_induction,  mul-list_wf,  subtype_rel_list,  list_wf,  null_nil_lemma,  btrue_wf,  member-implies-null-eq-bfalse,  nil_wf,  btrue_neq_bfalse,  cons_wf,  cons_member,  list_subtype_base,  mul_list_nil_lemma,  length_of_cons_lemma,  add_nat_plus,  length_wf_nat,  nat_plus_properties,  add-is-int-iff,  false_wf,  length_wf,  equal-wf-T-base,  int_nzero_wf,  exists_wf,  absval_wf,  int_term_value_minus_lemma,  itermMinus_wf,  assert-bnot,  bool_subtype_base,  bool_cases_sqequal,  eqff_to_assert,  int_nzero_properties,  top_wf,  assert_of_lt_int,  eqtt_to_assert,  bool_wf,  lt_int_wf,  absval_unfold,  absval_square,  absval-non-neg,  absval_mul
Rules used in proof :  cut,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  setElimination,  rename,  productElimination,  hypothesis,  hypothesisEquality,  natural_numberEquality,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation_alt,  lambdaEquality_alt,  int_eqEquality,  dependent_functionElimination,  isect_memberEquality_alt,  voidElimination,  sqequalRule,  independent_pairFormation,  universeIsType,  unionElimination,  applyEquality,  instantiate,  because_Cache,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  dependent_set_memberEquality_alt,  productIsType,  hypothesis_subsumption,  cumulativity,  intEquality,  inhabitedIsType,  productEquality,  multiplyEquality,  equalityIstype,  baseApply,  closedConclusion,  baseClosed,  sqequalBase,  functionIsType,  functionEquality,  addEquality,  imageElimination,  setIsType,  promote_hyp,  setEquality,  imageMemberEquality,  universeEquality,  inrFormation_alt,  pointwiseFunctionality,  lambdaEquality,  lambdaFormation,  dependent_pairFormation,  voidEquality,  isect_memberEquality,  axiomSqEquality,  isect_memberFormation,  lessCases,  equalityElimination,  minusEquality,  dependent_set_memberEquality,  sqequalIntensionalEquality

Latex:
\mforall{}n:\mBbbN{}.  ((\mexists{}x:\mBbbZ{}\msupminus{}\msupzero{}.  \mexists{}w,y:\mBbbZ{}.  ((n  *  x  *  x)  =  ((w  *  w)  +  (y  *  y))))  {}\mRightarrow{}  (\mexists{}a,b:\mBbbZ{}.  (n  =  ((a  *  a)  +  (b  *  b)))))



Date html generated: 2019_10_15-AM-11_12_43
Last ObjectModification: 2019_06_26-PM-04_24_32

Theory : general


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