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: y real: uall: [x:A]. B[x]
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T rleq: x ≤ y iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q implies:  Q rnonneg: rnonneg(x) all: x:A. B[x] le: A ≤ B not: ¬A false: False subtype_rel: A ⊆B real: prop: rsub: 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: + 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: supposing a nat: so_apply: x[s] decidable: Dec(P) or: P ∨ Q uiff: uiff(P;Q) top: Top subtract: m satisfiable_int_formula: satisfiable_int_formula(fmla) rev_uimplies: rev_uimplies(P;Q) ge: i ≥ 
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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