Nuprl Lemma : gcd-non-neg

∀[y,x:ℕ].  (0 ≤ gcd(x;y))


Proof




Definitions occuring in Statement :  gcd: gcd(a;b),  nat: ℕ,  uall: ∀[x:A]. B[x],  le: A ≤ B,  natural_number: $n
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  all: ∀x:A. B[x],  decidable: Dec(P),  or: P ∨ Q,  le: A ≤ B,  and: P ∧ Q,  not: ¬A,  implies: P ⇒ Q,  false: False,  nat: ℕ,  prop: ℙ,  uimplies: b supposing a,  sq_type: SQType(T),  guard: {T},  gcd: gcd(a;b),  eq_int: (i =z j),  ifthenelse: if b then t else f fi ,  btrue: tt,  ge: i ≥ j ,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  less_than': less_than'(a;b),  nequal: a ≠ b ∈ T ,  int_upper: {i...},  bool: 𝔹,  unit: Unit,  it: ⋅,  uiff: uiff(P;Q),  bfalse: ff,  bnot: ¬bb,  assert: ↑b,  subtype_rel: A ⊆r B,  int_nzero: ℤ-o,  so_lambda: λ2x.t[x],  so_apply: x[s],  less_than: a < b,  squash: ↓T
Lemmas referenced :  decidable__equal_int,  less_than'_wf,  gcd_wf,  nat_wf,  subtype_base_sq,  int_subtype_base,  nat_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  int_upper_subtype_nat,  false_wf,  le_wf,  nequal-le-implies,  zero-add,  eq_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_eq_int,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  bool_subtype_base,  assert-bnot,  neg_assert_of_eq_int,  zero-rem,  subtype_rel_sets,  nequal_wf,  int_upper_properties,  intformeq_wf,  int_formula_prop_eq_lemma,  equal-wf-base,  gcd-positive,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  because_Cache,  natural_numberEquality,  hypothesis,  unionElimination,  sqequalRule,  productElimination,  independent_pairEquality,  lambdaEquality,  hypothesisEquality,  isectElimination,  setElimination,  rename,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  isect_memberEquality,  voidElimination,  instantiate,  cumulativity,  intEquality,  independent_isectElimination,  independent_functionElimination,  dependent_pairFormation,  int_eqEquality,  voidEquality,  independent_pairFormation,  computeAll,  hypothesis_subsumption,  dependent_set_memberEquality,  lambdaFormation,  equalityElimination,  promote_hyp,  applyEquality,  setEquality,  applyLambdaEquality,  baseClosed,  imageElimination

Latex:
\mforall{}[y,x:\mBbbN{}].    (0  \mleq{}  gcd(x;y))



Date html generated: 2017_04_17-AM-09_45_50
Last ObjectModification: 2017_02_27-PM-05_40_34

Theory : num_thy_1


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