Nuprl Lemma : scale-metric-cauchy
∀[X:Type]. ∀[d:metric(X)].  ∀c:{c:ℝ| r0 < c} . ∀x:ℕ ⟶ X.  (mcauchy(d;n.x n) 
⇐⇒ mcauchy(c*d;n.x n))
Proof
Definitions occuring in Statement : 
mcauchy: mcauchy(d;n.x[n])
, 
scale-metric: c*d
, 
metric: metric(X)
, 
rless: x < y
, 
int-to-real: r(n)
, 
real: ℝ
, 
nat: ℕ
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
set: {x:A| B[x]} 
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
natural_number: $n
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
subtype_rel: A ⊆r B
, 
metric-leq: d1 ≤ d2
, 
uimplies: b supposing a
, 
rleq: x ≤ y
, 
rnonneg: rnonneg(x)
, 
le: A ≤ B
, 
metric: metric(X)
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
rneq: x ≠ y
, 
guard: {T}
, 
or: P ∨ Q
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
less_than: a < b
, 
less_than': less_than'(a;b)
, 
true: True
, 
rdiv: (x/y)
, 
uiff: uiff(P;Q)
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
not: ¬A
, 
top: Top
, 
scale-metric: c*d
, 
mdist: mdist(d;x;y)
, 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
metric-leq-cauchy, 
scale-metric_wf, 
rleq_weakening_equal, 
mdist_wf, 
le_witness_for_triv, 
mcauchy_wf, 
istype-nat, 
rdiv_wf, 
int-to-real_wf, 
sq_stable__rless, 
rless_wf, 
subtype_rel_sets_simple, 
real_wf, 
rleq_wf, 
rleq_weakening_rless, 
metric_wf, 
istype-universe, 
rmul_preserves_rless, 
rmul_wf, 
itermSubtract_wf, 
itermMultiply_wf, 
itermConstant_wf, 
itermVar_wf, 
rinv_wf2, 
rless-int, 
rless_functionality, 
req_transitivity, 
rmul-rinv, 
req-iff-rsub-is-0, 
real_polynomial_null, 
istype-int, 
real_term_value_sub_lemma, 
istype-void, 
real_term_value_mul_lemma, 
real_term_value_const_lemma, 
real_term_value_var_lemma, 
rleq_functionality, 
req_weakening, 
rmul_functionality
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
lambdaFormation_alt, 
independent_pairFormation, 
applyEquality, 
because_Cache, 
sqequalRule, 
dependent_functionElimination, 
independent_functionElimination, 
independent_isectElimination, 
lambdaEquality_alt, 
productElimination, 
equalityTransitivity, 
equalitySymmetry, 
functionIsTypeImplies, 
inhabitedIsType, 
universeIsType, 
setElimination, 
rename, 
dependent_set_memberEquality_alt, 
closedConclusion, 
natural_numberEquality, 
inrFormation_alt, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
functionIsType, 
setIsType, 
instantiate, 
universeEquality, 
approximateComputation, 
int_eqEquality, 
isect_memberEquality_alt, 
voidElimination
Latex:
\mforall{}[X:Type].  \mforall{}[d:metric(X)].    \mforall{}c:\{c:\mBbbR{}|  r0  <  c\}  .  \mforall{}x:\mBbbN{}  {}\mrightarrow{}  X.    (mcauchy(d;n.x  n)  \mLeftarrow{}{}\mRightarrow{}  mcauchy(c*d;n.x  n))
Date html generated:
2019_10_30-AM-06_44_55
Last ObjectModification:
2019_10_02-AM-10_56_50
Theory : reals
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