Nuprl Lemma : rmax-minus-rmin

∀a,b:ℝ.  (|a - b| = (rmax(a;b) - rmin(a;b)))


Proof




Definitions occuring in Statement :  rabs: |x|,  rmin: rmin(x;y),  rmax: rmax(x;y),  rsub: x - y,  req: x = y,  real: ℝ,  all: ∀x:A. B[x]
Definitions unfolded in proof :  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x],  member: t ∈ T,  top: Top,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  rsub: x - y,  subtype_rel: A ⊆r B,  real: ℝ,  rminus: -(x),  rmax: rmax(x;y),  rmin: rmin(x;y),  bdd-diff: bdd-diff(f;g),  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  exists: ∃x:A. B[x],  nat: ℕ,  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  not: ¬A,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  true: True,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  ifthenelse: if b then t else f fi ,  bfalse: ff,  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  nat_plus: ℕ+,  satisfiable_int_formula: satisfiable_int_formula(fmla),  less_than: a < b,  squash: ↓T,  subtract: n - m
Lemmas referenced :  rabs-as-rmax,  real_wf,  req-iff-bdd-diff,  rmax_wf,  rsub_wf,  rminus_wf,  rmin_wf,  radd_wf,  imax_wf,  nat_plus_wf,  bdd-diff_functionality,  rmax_functionality_wrt_bdd-diff,  rminus_functionality_wrt_bdd-diff,  radd-bdd-diff,  false_wf,  le_wf,  all_wf,  absval_wf,  subtract_wf,  imin_wf,  ifthenelse_wf,  le_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_le_int,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  nat_plus_properties,  add-is-int-iff,  minus-is-int-iff,  full-omega-unsat,  intformand_wf,  intformle_wf,  itermAdd_wf,  itermVar_wf,  itermMinus_wf,  intformnot_wf,  int_formula_prop_and_lemma,  int_formula_prop_le_lemma,  int_term_value_add_lemma,  int_term_value_var_lemma,  int_term_value_minus_lemma,  int_formula_prop_not_lemma,  int_formula_prop_wf,  absval_unfold,  top_wf,  less_than_wf,  squash_wf,  true_wf,  imax_unfold,  add_functionality_wrt_eq,  minus_functionality_wrt_eq,  imin_unfold,  nat_wf,  subtype_rel_self,  iff_weakening_equal,  minus-add,  minus-minus,  add-associates,  minus-one-mul,  add-mul-special,  add-commutes,  add-swap,  zero-mul,  zero-add
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  sqequalRule,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  isect_memberEquality,  voidElimination,  voidEquality,  hypothesis,  hypothesisEquality,  productElimination,  independent_isectElimination,  applyEquality,  lambdaEquality,  setElimination,  rename,  addEquality,  because_Cache,  minusEquality,  dependent_functionElimination,  independent_functionElimination,  dependent_pairFormation,  dependent_set_memberEquality,  natural_numberEquality,  independent_pairFormation,  intEquality,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  promote_hyp,  instantiate,  cumulativity,  pointwiseFunctionality,  baseApply,  closedConclusion,  baseClosed,  approximateComputation,  int_eqEquality,  multiplyEquality,  lessCases,  imageMemberEquality,  isect_memberFormation,  axiomSqEquality,  imageElimination,  universeEquality

Latex:
\mforall{}a,b:\mBbbR{}.    (|a  -  b|  =  (rmax(a;b)  -  rmin(a;b)))



Date html generated: 2019_10_29-AM-09_39_00
Last ObjectModification: 2018_08_20-PM-09_46_50

Theory : reals


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