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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