Nuprl Lemma : absval_lbound

i:ℤ. ∀n:ℕ.  (|i| > ⇐⇒ i < -n ∨ (i > n))


Proof




Definitions occuring in Statement :  absval: |i| nat: less_than: a < b gt: i > j all: x:A. B[x] iff: ⇐⇒ Q or: P ∨ Q minus: -n int:
Definitions unfolded in proof :  all: x:A. B[x] uall: [x:A]. B[x] member: t ∈ T implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a less_than: a < b less_than': less_than'(a;b) top: Top true: True squash: T not: ¬A false: False prop: iff: ⇐⇒ Q nat: decidable: Dec(P) or: P ∨ Q rev_implies:  Q gt: i > j guard: {T} subtype_rel: A ⊆B le: A ≤ B bfalse: ff exists: x:A. B[x] sq_type: SQType(T) bnot: ¬bb ifthenelse: if then else fi  assert: b ge: i ≥  subtract: m sq_stable: SqStable(P)
Lemmas referenced :  absval_unfold2 lt_int_wf bool_wf eqtt_to_assert assert_of_lt_int top_wf less_than_wf decidable__lt gt_wf false_wf not-lt-2 minus-le not-gt-2 less-iff-le add_functionality_wrt_le add-associates add-commutes le-add-cancel or_wf eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base iff_transitivity assert_wf bnot_wf not_wf iff_weakening_uiff assert_of_bnot nat_wf add_functionality_wrt_lt le_reflexive minus-one-mul add-mul-special zero-mul nat_properties condition-implies-le minus-add add-swap minus-one-mul-top add-zero minus-zero zero-add two-mul subtract_wf sq_stable_from_decidable le_wf decidable__le
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation sqequalRule cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis natural_numberEquality unionElimination equalityElimination equalityTransitivity equalitySymmetry productElimination independent_isectElimination because_Cache lessCases isect_memberFormation sqequalAxiom isect_memberEquality independent_pairFormation voidElimination voidEquality imageMemberEquality baseClosed imageElimination independent_functionElimination dependent_functionElimination minusEquality setElimination rename inlFormation inrFormation addEquality applyEquality addLevel orFunctionality dependent_pairFormation promote_hyp instantiate cumulativity impliesFunctionality intEquality multiplyEquality lambdaEquality

Latex:
\mforall{}i:\mBbbZ{}.  \mforall{}n:\mBbbN{}.    (|i|  >  n  \mLeftarrow{}{}\mRightarrow{}  i  <  -n  \mvee{}  (i  >  n))



Date html generated: 2017_04_14-AM-07_17_12
Last ObjectModification: 2017_02_27-PM-02_52_09

Theory : arithmetic


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