Nuprl Lemma : olympiad-problem-six

∀k:ℤ. ∀a,b:ℕ.  ((((a * a) + (b * b)) = (k * ((a * b) + 1)) ∈ ℤ) ⇒ (∃n:ℤ. (k = (n * n) ∈ ℤ)))


Proof




Definitions occuring in Statement :  nat: ℕ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  multiply: n * m,  add: n + m,  natural_number: $n,  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+
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,  itermAdd_wf,  itermMultiply_wf,  int_term_value_add_lemma,  int_term_value_mul_lemma,  le_wf,  nat_wf,  equal-wf-base,  lelt_wf,  primrec-wf2,  istype-nat,  mul_bounds_1a,  mul_cancel_in_le,  add_nat_plus,  multiply_nat_wf,  nat_plus_properties,  mul_preserves_le,  square_non_neg,  mul_cancel_in_lt
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :lambdaFormation_alt,  cut,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  setElimination,  rename,  productElimination,  hypothesis,  hypothesisEquality,  natural_numberEquality,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  Error :dependent_pairFormation_alt,  Error :lambdaEquality_alt,  int_eqEquality,  dependent_functionElimination,  Error :isect_memberEquality_alt,  voidElimination,  sqequalRule,  independent_pairFormation,  Error :universeIsType,  unionElimination,  applyEquality,  instantiate,  because_Cache,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  Error :dependent_set_memberEquality_alt,  Error :productIsType,  hypothesis_subsumption,  cumulativity,  intEquality,  Error :equalityIstype,  baseApply,  closedConclusion,  baseClosed,  Error :inhabitedIsType,  sqequalBase,  Error :functionIsType,  functionEquality,  productEquality,  Error :setIsType,  addEquality,  multiplyEquality

Latex:
\mforall{}k:\mBbbZ{}.  \mforall{}a,b:\mBbbN{}.    ((((a  *  a)  +  (b  *  b))  =  (k  *  ((a  *  b)  +  1)))  {}\mRightarrow{}  (\mexists{}n:\mBbbZ{}.  (k  =  (n  *  n))))



Date html generated: 2019_06_20-PM-02_43_07
Last ObjectModification: 2019_03_10-PM-02_32_31

Theory : num_thy_1


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