Nuprl Lemma : absval_strict_ubound

[i:ℤ]. ∀[n:ℕ].  uiff(|i| < n;-n < i ∧ i < n)


Proof




Definitions occuring in Statement :  absval: |i| nat: less_than: a < b uiff: uiff(P;Q) uall: [x:A]. B[x] and: P ∧ Q minus: -n int:
Definitions unfolded in proof :  subtract: m decidable: Dec(P) le: A ≤ B rev_implies:  Q iff: ⇐⇒ Q assert: b ifthenelse: if then else fi  bnot: ¬bb guard: {T} sq_type: SQType(T) or: P ∨ Q exists: x:A. B[x] bfalse: ff false: False not: ¬A squash: T true: True less_than': less_than'(a;b) less_than: a < b btrue: tt it: unit: Unit bool: 𝔹 implies:  Q uiff: uiff(P;Q) prop: and: P ∧ Q subtype_rel: A ⊆B top: Top all: x:A. B[x] uimplies: supposing a ge: i ≥  nat: member: t ∈ T uall: [x:A]. B[x]
Lemmas referenced :  subtract_wf less_than_transitivity1 one-mul mul-distributes-right mul-commutes le_wf mul_preserves_le le-add-cancel minus-add condition-implies-le less-iff-le not-le-2 decidable__le add-zero add_functionality_wrt_lt le-add-cancel-alt add-swap add-commutes add-associates false_wf minus-one-mul-top decidable__lt not-lt-2 assert_of_bnot iff_weakening_uiff not_wf bnot_wf assert_wf iff_transitivity bool_subtype_base subtype_base_sq bool_cases_sqequal equal_wf eqff_to_assert top_wf assert_of_lt_int eqtt_to_assert bool_wf lt_int_wf zero-mul add-mul-special zero-add minus-one-mul member-less_than nat_wf absval_wf less_than_wf le_reflexive add_functionality_wrt_le nat_properties absval_unfold
Rules used in proof :  dependent_set_memberEquality addEquality impliesFunctionality cumulativity instantiate promote_hyp dependent_pairFormation independent_functionElimination imageElimination baseClosed imageMemberEquality independent_pairFormation sqequalAxiom lessCases equalityElimination unionElimination lambdaFormation equalitySymmetry equalityTransitivity independent_pairEquality isect_memberFormation intEquality productEquality productElimination lambdaEquality applyEquality voidEquality voidElimination isect_memberEquality multiplyEquality dependent_functionElimination independent_isectElimination because_Cache minusEquality natural_numberEquality rename setElimination hypothesis hypothesisEquality thin isectElimination sqequalReflexivity computationStep sqequalTransitivity sqequalHypSubstitution extract_by_obid introduction cut sqequalRule sqequalSubstitution

Latex:
\mforall{}[i:\mBbbZ{}].  \mforall{}[n:\mBbbN{}].    uiff(|i|  <  n;-n  <  i  \mwedge{}  i  <  n)



Date html generated: 2017_09_29-PM-05_47_06
Last ObjectModification: 2017_09_12-PM-00_00_09

Theory : arithmetic


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