Nuprl Lemma : i-member-convex'
∀I:Interval. ∀a,b:ℝ.
  ((a ∈ I) 
⇒ (b ∈ I) 
⇒ (∀z:{z:ℝ| r0 < z} . ∀x,y:{z:ℝ| r0 ≤ z} .  (((x + y) = z) 
⇒ (((x * a) + (y * b)/z) ∈ I))))
Proof
Definitions occuring in Statement : 
i-member: r ∈ I
, 
interval: Interval
, 
rdiv: (x/y)
, 
rleq: x ≤ y
, 
rless: x < y
, 
req: x = y
, 
rmul: a * b
, 
radd: a + b
, 
int-to-real: r(n)
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
set: {x:A| B[x]} 
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
rneq: x ≠ y
, 
guard: {T}
, 
or: P ∨ Q
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
prop: ℙ
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
rev_uimplies: rev_uimplies(P;Q)
, 
rdiv: (x/y)
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
not: ¬A
, 
top: Top
, 
iff: P 
⇐⇒ Q
Lemmas referenced : 
i-member-convex, 
rdiv_wf, 
sq_stable__rless, 
int-to-real_wf, 
rless_wf, 
req_wf, 
radd_wf, 
rleq_wf, 
i-member_wf, 
real_wf, 
interval_wf, 
rmul_preserves_rleq, 
rmul_wf, 
itermSubtract_wf, 
itermMultiply_wf, 
itermConstant_wf, 
itermVar_wf, 
rinv_wf2, 
sq_stable__rleq, 
rleq_functionality, 
req_transitivity, 
rmul_functionality, 
req_weakening, 
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, 
trivial-rleq-radd, 
req_inversion, 
rmul_preserves_req, 
rsub_wf, 
rminus_wf, 
itermAdd_wf, 
itermMinus_wf, 
req_functionality, 
radd_functionality, 
rminus_functionality, 
real_term_value_add_lemma, 
real_term_value_minus_lemma, 
req-implies-req, 
i-member_functionality
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
independent_functionElimination, 
hypothesis, 
isectElimination, 
setElimination, 
rename, 
because_Cache, 
independent_isectElimination, 
sqequalRule, 
inrFormation_alt, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
universeIsType, 
inhabitedIsType, 
setIsType, 
productElimination, 
approximateComputation, 
lambdaEquality_alt, 
int_eqEquality, 
isect_memberEquality_alt, 
voidElimination, 
equalityTransitivity, 
equalitySymmetry, 
closedConclusion
Latex:
\mforall{}I:Interval.  \mforall{}a,b:\mBbbR{}.
    ((a  \mmember{}  I)
    {}\mRightarrow{}  (b  \mmember{}  I)
    {}\mRightarrow{}  (\mforall{}z:\{z:\mBbbR{}|  r0  <  z\}  .  \mforall{}x,y:\{z:\mBbbR{}|  r0  \mleq{}  z\}  .    (((x  +  y)  =  z)  {}\mRightarrow{}  (((x  *  a)  +  (y  *  b)/z)  \mmember{}  I))))
Date html generated:
2019_10_29-AM-10_46_52
Last ObjectModification:
2019_01_08-PM-06_10_39
Theory : reals
Home
Index