Nuprl Lemma : even-succ-implies-not-even

∀n:ℤ. ((↑isEven(n + 1)) ⇒ (¬↑isEven(n)))


Proof




Definitions occuring in Statement :  isEven: isEven(n),  assert: ↑b,  all: ∀x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  add: n + m,  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  isEven: isEven(n),  all: ∀x:A. B[x],  implies: P ⇒ Q,  not: ¬A,  false: False,  uall: ∀[x:A]. B[x],  member: t ∈ T,  subtype_rel: A ⊆r B,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  rev_uimplies: rev_uimplies(P;Q),  squash: ↓T,  prop: ℙ,  true: True,  guard: {T},  iff: P ⇐⇒ Q,  nequal: a ≠ b ∈ T ,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  int_nzero: ℤ-o,  sq_type: SQType(T)
Lemmas referenced :  assert_of_eq_int,  modulus_wf,  neg_assert_of_eq_int,  equal_wf,  squash_wf,  true_wf,  add-one-mod-2,  iff_weakening_equal,  satisfiable-full-omega-tt,  intformand_wf,  intformeq_wf,  itermVar_wf,  itermConstant_wf,  itermSubtract_wf,  int_formula_prop_and_lemma,  int_formula_prop_eq_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_term_value_subtract_lemma,  int_formula_prop_wf,  equal-wf-base,  int_subtype_base,  assert_wf,  eq_int_wf,  subtype_base_sq,  nequal_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  lambdaFormation,  cut,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  because_Cache,  hypothesis,  applyEquality,  natural_numberEquality,  productElimination,  independent_isectElimination,  equalityTransitivity,  equalitySymmetry,  lambdaEquality,  imageElimination,  hypothesisEquality,  universeEquality,  intEquality,  imageMemberEquality,  baseClosed,  independent_functionElimination,  dependent_pairFormation,  int_eqEquality,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  computeAll,  baseApply,  closedConclusion,  dependent_set_memberEquality,  addLevel,  instantiate,  cumulativity,  addEquality

Latex:
\mforall{}n:\mBbbZ{}.  ((\muparrow{}isEven(n  +  1))  {}\mRightarrow{}  (\mneg{}\muparrow{}isEven(n)))



Date html generated: 2017_04_17-AM-09_43_20
Last ObjectModification: 2017_02_27-PM-05_37_57

Theory : num_thy_1


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