Nuprl Lemma : gcd_wf

∀a,b:ℤ.  (gcd(a;b) ∈ ℤ)


Proof




Definitions occuring in Statement :  gcd: gcd(a;b),  all: ∀x:A. B[x],  member: t ∈ T,  int: ℤ
Definitions unfolded in proof :  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x],  member: t ∈ T,  nat: ℕ,  implies: P ⇒ Q,  false: False,  ge: i ≥ j ,  guard: {T},  uimplies: b supposing a,  prop: ℙ,  subtype_rel: A ⊆r B,  le: A ≤ B,  and: P ∧ Q,  decidable: Dec(P),  or: P ∨ Q,  iff: P ⇐⇒ Q,  not: ¬A,  rev_implies: P ⇐ Q,  uiff: uiff(P;Q),  subtract: n - m,  top: Top,  less_than': less_than'(a;b),  true: True,  gcd: gcd(a;b),  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  ifthenelse: if b then t else f fi ,  bfalse: ff,  exists: ∃x:A. B[x],  sq_type: SQType(T),  bnot: ¬bb,  assert: ↑b,  nequal: a ≠ b ∈ T ,  int_nzero: ℤ-o
Lemmas referenced :  nat_properties,  less_than_transitivity1,  less_than_irreflexivity,  ge_wf,  less_than_wf,  absval_wf,  nat_wf,  absval-non-neg,  decidable__le,  subtract_wf,  false_wf,  not-ge-2,  less-iff-le,  condition-implies-le,  minus-one-mul,  zero-add,  minus-one-mul-top,  minus-add,  minus-minus,  add-associates,  add-swap,  add-commutes,  add_functionality_wrt_le,  add-zero,  le-add-cancel,  eq_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_eq_int,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  iff_transitivity,  assert_wf,  bnot_wf,  not_wf,  equal-wf-base,  int_subtype_base,  iff_weakening_uiff,  assert_of_bnot,  rem_bounds_z,  nequal_wf,  decidable__lt,  not-lt-2,  not-le-2,  le_wf,  add-mul-special,  zero-mul
Rules used in proof :  cut,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  setElimination,  rename,  sqequalRule,  intWeakElimination,  natural_numberEquality,  independent_isectElimination,  independent_functionElimination,  voidElimination,  lambdaEquality,  dependent_functionElimination,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  applyEquality,  intEquality,  productElimination,  because_Cache,  unionElimination,  independent_pairFormation,  addEquality,  isect_memberEquality,  voidEquality,  minusEquality,  equalityElimination,  dependent_pairFormation,  promote_hyp,  instantiate,  cumulativity,  baseClosed,  impliesFunctionality,  remainderEquality,  dependent_set_memberEquality,  multiplyEquality

Latex:
\mforall{}a,b:\mBbbZ{}.    (gcd(a;b)  \mmember{}  \mBbbZ{})



Date html generated: 2017_04_14-AM-07_18_48
Last ObjectModification: 2017_02_27-PM-02_52_44

Theory : arithmetic


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