Nuprl Lemma : absval_square

∀[x:ℤ]. (|x * x| = (x * x) ∈ 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],  all: ∀x:A. B[x],  member: t ∈ T,  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,  prop: ℙ,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  assert: ↑b,  satisfiable_int_formula: satisfiable_int_formula(fmla)
Lemmas referenced :  square_non_neg,  absval_unfold,  lt_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_lt_int,  top_wf,  less_than_wf,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  satisfiable-full-omega-tt,  intformand_wf,  intformle_wf,  itermConstant_wf,  itermMultiply_wf,  itermVar_wf,  intformnot_wf,  intformless_wf,  int_formula_prop_and_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_mul_lemma,  int_term_value_var_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  hypothesis,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  sqequalRule,  isectElimination,  multiplyEquality,  minusEquality,  natural_numberEquality,  lambdaFormation,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  productElimination,  independent_isectElimination,  because_Cache,  lessCases,  sqequalAxiom,  isect_memberEquality,  independent_pairFormation,  voidElimination,  voidEquality,  imageMemberEquality,  baseClosed,  imageElimination,  independent_functionElimination,  dependent_pairFormation,  promote_hyp,  instantiate,  cumulativity,  lambdaEquality,  int_eqEquality,  intEquality,  computeAll

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



Date html generated: 2017_04_14-AM-09_15_35
Last ObjectModification: 2017_02_27-PM-03_53_07

Theory : int_2


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