Nuprl Lemma : exp-minus

∀[n:ℕ]. ∀[x:ℤ].  ((-x)^n = if (n mod 2 =z 0) then x^n else -x^n fi  ∈ ℤ)


Proof




Definitions occuring in Statement :  exp: i^n,  modulus: a mod n,  nat: ℕ,  ifthenelse: if b then t else f fi ,  eq_int: (i =z j),  uall: ∀[x:A]. B[x],  minus: -n,  natural_number: $n,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  ifthenelse: if b then t else f fi ,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  bfalse: ff,  exists: ∃x:A. B[x],  prop: ℙ,  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  false: False,  true: True,  nat: ℕ,  ge: i ≥ j ,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  not: ¬A,  top: Top,  nequal: a ≠ b ∈ T ,  squash: ↓T,  subtype_rel: A ⊆r B,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  minus-one-mul,  exp_wf2,  bool_wf,  eqtt_to_assert,  assert_of_eq_int,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  neg_assert_of_eq_int,  nat_properties,  decidable__equal_int,  le_wf,  satisfiable-full-omega-tt,  intformnot_wf,  intformeq_wf,  itermMultiply_wf,  itermConstant_wf,  itermVar_wf,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_mul_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  itermMinus_wf,  int_term_value_minus_lemma,  squash_wf,  true_wf,  exp-of-mul,  exp-minusone,  iff_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  because_Cache,  sqequalRule,  isect_memberEquality,  axiomEquality,  minusEquality,  natural_numberEquality,  lambdaFormation,  unionElimination,  equalityElimination,  productElimination,  independent_isectElimination,  equalityTransitivity,  equalitySymmetry,  dependent_pairFormation,  promote_hyp,  dependent_functionElimination,  instantiate,  cumulativity,  independent_functionElimination,  voidElimination,  setElimination,  rename,  dependent_set_memberEquality,  lambdaEquality,  int_eqEquality,  intEquality,  voidEquality,  computeAll,  applyEquality,  imageElimination,  universeEquality,  multiplyEquality,  imageMemberEquality,  baseClosed

Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[x:\mBbbZ{}].    ((-x)\^{}n  =  if  (n  mod  2  =\msubz{}  0)  then  x\^{}n  else  -x\^{}n  fi  )



Date html generated: 2018_05_21-PM-01_05_21
Last ObjectModification: 2018_01_28-PM-02_01_53

Theory : num_thy_1


Home Index