Nuprl Lemma : int-with-rational-square-root

∀n:ℤ. ∀q:ℚ.  (((q * q) = n ∈ ℚ) ⇒ (∃m:ℤ. ((m * m) = n ∈ ℤ)))


Proof




Definitions occuring in Statement :  qmul: r * s,  rationals: ℚ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  multiply: n * m,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  subtype_rel: A ⊆r B,  squash: ↓T,  prop: ℙ,  true: True,  uimplies: b supposing a,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  pi1: fst(t),  pi2: snd(t),  mk-rational: mk-rational(a;b),  rationals: ℚ,  quotient: x,y:A//B[x; y],  nat_plus: ℕ+,  so_lambda: λ2x.t[x],  so_apply: x[s],  ifthenelse: if b then t else f fi ,  bfalse: ff,  btrue: tt,  uiff: uiff(P;Q),  exists: ∃x:A. B[x],  cand: A c∧ B,  coprime: CoPrime(a,b),  gcd_p: GCD(a;b;y),  sq_type: SQType(T),  not: ¬A,  false: False,  or: P ∨ Q,  divides: b | a,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  prime: prime(a),  assoced: a ~ b,  int_upper: {i...},  label: ...$L... t,  sq_exists: ∃x:A [B[x]],  cons: [a / b],  mul-list: Π(ns) ,  reduce: reduce(f;k;as),  list_ind: list_ind
Lemmas referenced :  qmul_wf,  int-subtype-rationals,  rationals_wf,  istype-int,  equals-qrep,  qrep-coprime,  equal_wf,  squash_wf,  true_wf,  istype-universe,  subtype_rel_self,  iff_weakening_equal,  qrep_wf,  b-union_wf,  int_nzero_wf,  bool_wf,  qeq_wf2,  mk-rational_wf,  nat_plus_inc_int_nzero,  btrue_wf,  set_subtype_base,  less_than_wf,  int_subtype_base,  qeq-elim,  qmul-elim,  eqtt_to_assert,  assert_of_eq_int,  coprime_wf,  one_divs_any,  divides_wf,  gcd_is_gcd,  absval_ifthenelse,  gcd_wf,  lt_int_wf,  subtype_base_sq,  assert_wf,  bnot_wf,  not_wf,  istype-less_than,  istype-assert,  istype-void,  divides_invar_2,  bool_cases,  bool_subtype_base,  assert_of_lt_int,  eqff_to_assert,  iff_transitivity,  iff_weakening_uiff,  assert_of_bnot,  prime_wf,  prime_divs_prod,  nat_plus_properties,  decidable__equal_int,  full-omega-unsat,  intformnot_wf,  intformeq_wf,  itermMultiply_wf,  itermVar_wf,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_mul_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  nat_plus_wf,  decidable__equal_nat_plus,  decidable__lt,  intformless_wf,  itermConstant_wf,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  prime-factors,  decidable__le,  intformand_wf,  intformle_wf,  int_formula_prop_and_lemma,  int_formula_prop_le_lemma,  istype-le,  set_wf,  int_upper_wf,  list-cases,  product_subtype_list,  mul_list_nil_lemma,  mul-list_wf,  subtype_rel_list,  istype-int_upper,  le_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  equalityIstype,  inhabitedIsType,  hypothesisEquality,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesis,  applyEquality,  sqequalRule,  universeIsType,  lambdaEquality_alt,  imageElimination,  equalityTransitivity,  equalitySymmetry,  instantiate,  universeEquality,  natural_numberEquality,  imageMemberEquality,  baseClosed,  because_Cache,  independent_isectElimination,  productElimination,  independent_functionElimination,  dependent_functionElimination,  pertypeElimination,  promote_hyp,  productIsType,  intEquality,  productEquality,  sqequalBase,  baseApply,  closedConclusion,  isintReduceTrue,  multiplyEquality,  setElimination,  rename,  dependent_pairFormation_alt,  independent_pairFormation,  cumulativity,  functionIsType,  unionElimination,  voidElimination,  approximateComputation,  int_eqEquality,  Error :memTop,  dependent_set_memberEquality_alt,  hypothesis_subsumption,  setEquality,  setIsType

Latex:
\mforall{}n:\mBbbZ{}.  \mforall{}q:\mBbbQ{}.    (((q  *  q)  =  n)  {}\mRightarrow{}  (\mexists{}m:\mBbbZ{}.  ((m  *  m)  =  n)))



Date html generated: 2020_05_20-AM-09_31_06
Last ObjectModification: 2020_01_01-AM-11_44_42

Theory : rationals


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