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: y req: y real: 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: supposing a rsub: y subtype_rel: A ⊆B real: rminus: -(x) rmax: rmax(x;y) rmin: rmin(x;y) bdd-diff: bdd-diff(f;g) implies:  Q iff: ⇐⇒ Q rev_implies:  Q exists: x:A. B[x] nat: le: A ≤ B less_than': less_than'(a;b) false: False not: ¬A prop: so_lambda: λ2x.t[x] so_apply: x[s] true: True bool: 𝔹 unit: Unit it: btrue: tt ifthenelse: if then else fi  bfalse: ff or: P ∨ Q sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b nat_plus: + satisfiable_int_formula: satisfiable_int_formula(fmla) less_than: a < b squash: T subtract: 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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