Nuprl Lemma : rabs-difference-rmax

∀[a,b,x,y:ℝ].  (|rmax(x;y) - rmax(a;b)| ≤ rmax(|x - a|;|y - b|))


Proof




Definitions occuring in Statement :  rleq: x ≤ y,  rabs: |x|,  rmax: rmax(x;y),  rsub: x - y,  real: ℝ,  uall: ∀[x:A]. B[x]
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  rleq: x ≤ y,  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  rnonneg: rnonneg(x),  all: ∀x:A. B[x],  le: A ≤ B,  not: ¬A,  false: False,  subtype_rel: A ⊆r B,  real: ℝ,  prop: ℙ,  rsub: x - y,  reg-seq-add: reg-seq-add(x;y),  rmax: rmax(x;y),  rminus: -(x),  rabs: |x|,  rnonneg2: rnonneg2(x),  exists: ∃x:A. B[x],  nat_plus: ℕ+,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  so_lambda: λ2x.t[x],  int_upper: {i...},  guard: {T},  uimplies: b supposing a,  nat: ℕ,  so_apply: x[s],  decidable: Dec(P),  or: P ∨ Q,  uiff: uiff(P;Q),  top: Top,  subtract: n - m,  satisfiable_int_formula: satisfiable_int_formula(fmla),  rev_uimplies: rev_uimplies(P;Q),  ge: i ≥ j 
Lemmas referenced :  multiply_functionality_wrt_le,  le_weakening,  le_functionality,  nat_plus_subtype_nat,  int_formula_prop_wf,  int_term_value_var_lemma,  int_term_value_mul_lemma,  int_term_value_add_lemma,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermVar_wf,  itermMultiply_wf,  itermAdd_wf,  itermConstant_wf,  intformle_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__le,  nat_plus_properties,  int_upper_properties,  minus-one-mul-top,  minus-one-mul,  le-add-cancel,  zero-add,  add-commutes,  add_functionality_wrt_le,  not-lt-2,  false_wf,  decidable__lt,  absval-imax-difference,  nat_wf,  less_than_transitivity1,  le_wf,  all_wf,  int_upper_wf,  less_than_wf,  rminus_functionality_wrt_bdd-diff,  rabs_functionality_wrt_bdd-diff,  rmax_functionality_wrt_bdd-diff,  reg-seq-add_functionality_wrt_bdd-diff,  absval_wf,  imax_wf,  reg-seq-add_wf,  radd-bdd-diff,  rminus_wf,  radd_wf,  rnonneg2_functionality,  nat_plus_wf,  real_wf,  less_than'_wf,  rabs_wf,  rmax_wf,  rsub_wf,  rnonneg-iff
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  productElimination,  independent_functionElimination,  sqequalRule,  lambdaEquality,  dependent_functionElimination,  independent_pairEquality,  because_Cache,  applyEquality,  setElimination,  rename,  minusEquality,  natural_numberEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  isect_memberEquality,  voidElimination,  addEquality,  lambdaFormation,  dependent_pairFormation,  dependent_set_memberEquality,  independent_pairFormation,  imageMemberEquality,  baseClosed,  multiplyEquality,  independent_isectElimination,  unionElimination,  voidEquality,  intEquality,  int_eqEquality,  computeAll

Latex:
\mforall{}[a,b,x,y:\mBbbR{}].    (|rmax(x;y)  -  rmax(a;b)|  \mleq{}  rmax(|x  -  a|;|y  -  b|))



Date html generated: 2016_05_18-AM-07_17_23
Last ObjectModification: 2016_01_17-AM-01_57_27

Theory : reals


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