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

n:ℕ((∃x:ℤ-o. ∃w,y:ℤ((n x) ((w w) (y y)) ∈ ℤ))  (∃a,b:ℤ(n ((a a) (b b)) ∈ ℤ)))


Proof




Definitions occuring in Statement :  int_nzero: -o nat: all: x:A. B[x] exists: x:A. B[x] implies:  Q multiply: m add: m int: equal: 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: supposing a not: ¬A implies:  Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False top: Top prop: decidable: Dec(P) or: P ∨ Q subtype_rel: A ⊆B so_lambda: λ2x.t[x] so_apply: x[s] guard: {T} sq_type: SQType(T) nat: ge: i ≥  nat_plus: + cand: c∧ B less_than: a < b squash: T divides: a Prime: Prime int_upper: {i...} sq_stable: SqStable(P) less_than': less_than'(a;b) int_nzero: -o nequal: a ≠ b ∈  gt: i > j iff: ⇐⇒ Q rev_implies:  Q eqmod: a ≡ 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 then else 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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