Nuprl Lemma : ab-divides-a^2+b^2+1

∀a,b:ℤ.
  ((a * b) | (((a * a) + (b * b)) + 1)
  ⇐⇒ ∃n:ℕ. ((<|a|, |b|> = vexample(n;1;1) ∈ (ℤ × ℤ)) ∨ (<|b|, |a|> = vexample(n;1;1) ∈ (ℤ × ℤ))))


Proof




Definitions occuring in Statement :  vexample: vexample(n;a;b),  divides: b | a,  absval: |i|,  nat: ℕ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  or: P ∨ Q,  pair: <a, b>,  product: x:A × B[x],  multiply: n * m,  add: n + m,  natural_number: $n,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  subtype_rel: A ⊆r B,  prop: ℙ,  rev_implies: P ⇐ Q,  exists: ∃x:A. B[x],  or: P ∨ Q,  nat: ℕ,  so_lambda: λ2x.t[x],  so_apply: x[s],  uimplies: b supposing a,  squash: ↓T,  guard: {T},  true: True,  divides: b | a,  decidable: Dec(P),  le: A ≤ B,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  top: Top,  uiff: uiff(P;Q),  ge: i ≥ j ,  pi2: snd(t),  pi1: fst(t)
Lemmas referenced :  divides_wf,  absval_wf,  istype-nat,  int_subtype_base,  set_subtype_base,  le_wf,  istype-int,  absval-divides,  absval_mul,  iff_weakening_equal,  squash_wf,  true_wf,  add_functionality_wrt_eq,  absval_squared,  subtype_rel_self,  Vieta-jumping-example2-corollary,  decidable__le,  decidable__equal_int,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformeq_wf,  itermAdd_wf,  itermMultiply_wf,  itermVar_wf,  itermConstant_wf,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_add_lemma,  int_term_value_mul_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  add-is-int-iff,  multiply-is-int-iff,  intformle_wf,  int_formula_prop_le_lemma,  false_wf,  vexample_wf,  nat_properties,  istype-le,  pi2_wf,  pi1_wf,  nat_wf,  equal_wf,  istype-universe
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :lambdaFormation_alt,  cut,  thin,  independent_pairFormation,  Error :universeIsType,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  multiplyEquality,  hypothesisEquality,  hypothesis,  applyEquality,  because_Cache,  sqequalRule,  addEquality,  natural_numberEquality,  Error :productIsType,  Error :unionIsType,  Error :equalityIstype,  baseApply,  closedConclusion,  baseClosed,  intEquality,  Error :lambdaEquality_alt,  Error :inhabitedIsType,  independent_isectElimination,  sqequalBase,  equalitySymmetry,  productElimination,  independent_functionElimination,  promote_hyp,  dependent_functionElimination,  setElimination,  rename,  equalityTransitivity,  imageElimination,  imageMemberEquality,  instantiate,  universeEquality,  unionElimination,  approximateComputation,  Error :dependent_pairFormation_alt,  int_eqEquality,  Error :isect_memberEquality_alt,  voidElimination,  Error :inlFormation_alt,  pointwiseFunctionality,  Error :inrFormation_alt,  Error :dependent_set_memberEquality_alt,  applyLambdaEquality

Latex:
\mforall{}a,b:\mBbbZ{}.
    ((a  *  b)  |  (((a  *  a)  +  (b  *  b))  +  1)
    \mLeftarrow{}{}\mRightarrow{}  \mexists{}n:\mBbbN{}.  ((<|a|,  |b|>  =  vexample(n;1;1))  \mvee{}  (<|b|,  |a|>  =  vexample(n;1;1))))



Date html generated: 2019_06_20-PM-02_43_55
Last ObjectModification: 2019_03_11-PM-06_33_37

Theory : num_thy_1


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