Nuprl Lemma : exp-minus

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


Proof




Definitions occuring in Statement :  exp: i^n modulus: mod n nat: ifthenelse: if then else fi  eq_int: (i =z j) uall: [x:A]. B[x] minus: -n natural_number: $n int: equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T all: x:A. B[x] implies:  Q bool: 𝔹 unit: Unit it: btrue: tt ifthenelse: if then else fi  uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a bfalse: ff exists: x:A. B[x] prop: or: P ∨ Q sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b false: False true: True nat: ge: i ≥  decidable: Dec(P) satisfiable_int_formula: satisfiable_int_formula(fmla) not: ¬A top: Top nequal: a ≠ b ∈  squash: T subtype_rel: A ⊆B iff: ⇐⇒ Q rev_implies:  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


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