Nuprl Lemma : mod2-is-one

∀x:ℤ. ((x mod 2) = 1 ∈ ℤ ⇐⇒ ∃n:ℤ. (x = ((2 * n) + 1) ∈ ℤ))


Proof




Definitions occuring in Statement :  modulus: a mod n,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  multiply: n * m,  add: n + m,  natural_number: $n,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  so_apply: x[s],  so_lambda: λ2x.t[x],  decidable: Dec(P),  exists: ∃x:A. B[x],  bfalse: ff,  btrue: tt,  ifthenelse: if b then t else f fi ,  or: P ∨ Q,  less_than': less_than'(a;b),  le: A ≤ B,  uiff: uiff(P;Q),  top: Top,  subtract: n - m,  rev_implies: P ⇐ Q,  and: P ∧ Q,  iff: P ⇐⇒ Q,  subtype_rel: A ⊆r B,  prop: ℙ,  false: False,  guard: {T},  sq_type: SQType(T),  uimplies: b supposing a,  implies: P ⇒ Q,  not: ¬A,  nequal: a ≠ b ∈ T ,  true: True,  int_nzero: ℤ-o,  uall: ∀[x:A]. B[x],  member: t ∈ T,  all: ∀x:A. B[x]
Lemmas referenced :  iff_wf,  mod2-is-zero,  exists_wf,  minus-minus,  mul-associates,  minus-add,  not-equal-2,  false_wf,  decidable__int_equal,  assert_of_bnot,  iff_weakening_uiff,  iff_transitivity,  eqff_to_assert,  assert_of_eq_int,  eqtt_to_assert,  bool_subtype_base,  bool_wf,  bool_cases,  le-add-cancel,  add-zero,  add_functionality_wrt_le,  minus-one-mul-top,  minus-one-mul,  condition-implies-le,  le_antisymmetry_iff,  not_wf,  bnot_wf,  assert_wf,  zero-add,  add-commutes,  add-swap,  add-associates,  nequal_wf,  true_wf,  equal-wf-base,  int_subtype_base,  subtype_base_sq,  modulus_wf,  eq_int_wf,  subtract_wf,  mod2-add1
Rules used in proof :  promote_hyp,  multiplyEquality,  dependent_pairFormation,  impliesFunctionality,  unionElimination,  productElimination,  addEquality,  minusEquality,  voidEquality,  isect_memberEquality,  lambdaEquality,  closedConclusion,  baseApply,  independent_pairFormation,  sqequalRule,  because_Cache,  applyEquality,  baseClosed,  voidElimination,  independent_functionElimination,  equalitySymmetry,  equalityTransitivity,  independent_isectElimination,  cumulativity,  instantiate,  addLevel,  dependent_set_memberEquality,  hypothesis,  natural_numberEquality,  hypothesisEquality,  isectElimination,  thin,  dependent_functionElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  intEquality,  cut,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}x:\mBbbZ{}.  ((x  mod  2)  =  1  \mLeftarrow{}{}\mRightarrow{}  \mexists{}n:\mBbbZ{}.  (x  =  ((2  *  n)  +  1)))



Date html generated: 2018_07_25-PM-01_27_57
Last ObjectModification: 2018_06_27-PM-05_54_42

Theory : arithmetic


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