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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