Nuprl Lemma : absval_le_zero

[i:ℤ]. uiff(|i| ≤ 0;i 0 ∈ ℤ)


Proof




Definitions occuring in Statement :  absval: |i| uiff: uiff(P;Q) uall: [x:A]. B[x] le: A ≤ B 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 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 le: A ≤ B cand: c∧ B guard: {T} subtype_rel: A ⊆B bfalse: ff exists: x:A. B[x] or: P ∨ Q sq_type: SQType(T) bnot: ¬bb ifthenelse: if then else fi  assert: b iff: ⇐⇒ Q rev_implies:  Q prop: decidable: Dec(P) subtract: m
Lemmas referenced :  absval_unfold2 lt_int_wf eqtt_to_assert assert_of_lt_int istype-top istype-void less_than_transitivity1 less_than_irreflexivity istype-le le_weakening le_witness_for_triv int_subtype_base eqff_to_assert bool_cases_sqequal subtype_base_sq bool_wf bool_subtype_base iff_transitivity assert_wf bnot_wf not_wf less_than_wf iff_weakening_uiff assert_of_bnot istype-less_than istype-assert istype-int add_functionality_wrt_le le_reflexive decidable__int_equal istype-false not-equal-2 condition-implies-le minus-zero add-zero add-associates minus-add minus-minus minus-one-mul zero-add minus-one-mul-top two-mul add-commutes mul-distributes-right one-mul le-add-cancel not-lt-2
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity Error :isect_memberFormation_alt,  introduction cut sqequalRule extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis natural_numberEquality Error :inhabitedIsType,  Error :lambdaFormation_alt,  unionElimination equalityElimination equalityTransitivity equalitySymmetry productElimination independent_isectElimination because_Cache lessCases axiomSqEquality Error :isect_memberEquality_alt,  Error :isectIsTypeImplies,  independent_pairFormation voidElimination imageMemberEquality baseClosed imageElimination independent_functionElimination dependent_functionElimination Error :equalityIstype,  applyEquality sqequalBase Error :dependent_pairFormation_alt,  promote_hyp instantiate cumulativity Error :functionIsType,  Error :universeIsType,  independent_pairEquality axiomEquality minusEquality addEquality multiplyEquality intEquality

Latex:
\mforall{}[i:\mBbbZ{}].  uiff(|i|  \mleq{}  0;i  =  0)



Date html generated: 2019_06_20-AM-11_24_30
Last ObjectModification: 2019_02_12-PM-01_59_51

Theory : arithmetic


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