Nuprl Lemma : absval_mul

∀[x,y:ℤ].  (|x * y| = (|x| * |y|) ∈ ℤ)


Proof




Definitions occuring in Statement :  absval: |i|,  uall: ∀[x:A]. B[x],  multiply: n * m,  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,  bfalse: ff,  exists: ∃x:A. B[x],  subtype_rel: A ⊆r B,  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  assert: ↑b,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  prop: ℙ,  le: A ≤ B,  nat: ℕ,  subtract: n - m,  nat_plus: ℕ+,  decidable: Dec(P),  cand: A c∧ B
Lemmas referenced :  absval_unfold2,  lt_int_wf,  eqtt_to_assert,  assert_of_lt_int,  istype-top,  istype-void,  eqff_to_assert,  int_subtype_base,  bool_subtype_base,  bool_cases_sqequal,  subtype_base_sq,  iff_transitivity,  assert_wf,  bnot_wf,  not_wf,  less_than_wf,  iff_weakening_uiff,  assert_of_bnot,  istype-less_than,  istype-assert,  not-lt-2,  minus-one-mul,  mul-associates,  istype-int,  minus-one-mul-top,  mul-swap,  one-mul,  bool_wf,  less_than_irreflexivity,  less_than_transitivity1,  le_wf,  le_weakening2,  mul_preserves_le,  mul-commutes,  zero-mul,  le-add-cancel,  zero-add,  add-associates,  add_functionality_wrt_le,  add-commutes,  add-zero,  minus-zero,  minus-add,  condition-implies-le,  less-iff-le,  mul_preserves_lt,  decidable__int_equal,  decidable__lt,  istype-false,  not-equal-2,  add_functionality_wrt_lt,  le_reflexive,  add-mul-special
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  introduction,  cut,  sqequalRule,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  multiplyEquality,  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,  Error :dependent_pairFormation_alt,  Error :equalityIsType4,  baseApply,  closedConclusion,  applyEquality,  promote_hyp,  dependent_functionElimination,  instantiate,  Error :functionIsType,  Error :universeIsType,  Error :equalityIsType1,  minusEquality,  Error :lambdaEquality_alt,  cumulativity,  axiomEquality,  voidEquality,  isect_memberEquality,  dependent_set_memberEquality,  intEquality,  lambdaEquality,  addEquality

Latex:
\mforall{}[x,y:\mBbbZ{}].    (|x  *  y|  =  (|x|  *  |y|))



Date html generated: 2019_06_20-AM-11_24_38
Last ObjectModification: 2018_10_27-AM-11_38_11

Theory : arithmetic


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