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: 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,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b 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: A c∧ B,  guard: {T},  subtype_rel: A ⊆r B,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  assert: ↑b,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  prop: ℙ,  decidable: Dec(P),  subtract: n - 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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