Nuprl Lemma : rat2real-qavg
∀[a,b:ℚ].  (rat2real(qavg(a;b)) = (rat2real(a) + rat2real(b)/r(2)))
Proof
Definitions occuring in Statement : 
rat2real: rat2real(q)
, 
rdiv: (x/y)
, 
req: x = y
, 
radd: a + b
, 
int-to-real: r(n)
, 
uall: ∀[x:A]. B[x]
, 
natural_number: $n
, 
qavg: qavg(a;b)
, 
rationals: ℚ
Definitions unfolded in proof : 
rev_uimplies: rev_uimplies(P;Q)
, 
uiff: uiff(P;Q)
, 
false: False
, 
sq_type: SQType(T)
, 
not: ¬A
, 
nequal: a ≠ b ∈ T 
, 
int_nzero: ℤ-o
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
true: True
, 
less_than': less_than'(a;b)
, 
squash: ↓T
, 
less_than: a < b
, 
implies: P 
⇒ Q
, 
rev_implies: P 
⇐ Q
, 
and: P ∧ Q
, 
iff: P 
⇐⇒ Q
, 
all: ∀x:A. B[x]
, 
or: P ∨ Q
, 
guard: {T}
, 
rneq: x ≠ y
, 
uimplies: b supposing a
, 
qavg: qavg(a;b)
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
rat2real-qadd, 
rdiv_functionality, 
rat2real-qdiv, 
req_transitivity, 
req_functionality, 
req_weakening, 
nequal_wf, 
istype-int, 
int_subtype_base, 
subtype_base_sq, 
int_nzero-rational, 
qadd_wf, 
qdiv_wf, 
rationals_wf, 
rless_wf, 
rless-int, 
int-to-real_wf, 
radd_wf, 
rdiv_wf, 
qavg_wf, 
rat2real_wf, 
req_witness
Rules used in proof : 
sqequalBase, 
equalityIstype, 
voidElimination, 
equalitySymmetry, 
equalityTransitivity, 
intEquality, 
cumulativity, 
instantiate, 
lambdaFormation_alt, 
dependent_set_memberEquality_alt, 
applyEquality, 
isectIsTypeImplies, 
isect_memberEquality_alt, 
inhabitedIsType, 
universeIsType, 
baseClosed, 
imageMemberEquality, 
independent_pairFormation, 
independent_functionElimination, 
productElimination, 
because_Cache, 
dependent_functionElimination, 
inrFormation_alt, 
sqequalRule, 
independent_isectElimination, 
natural_numberEquality, 
closedConclusion, 
hypothesis, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
cut, 
introduction, 
isect_memberFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}[a,b:\mBbbQ{}].    (rat2real(qavg(a;b))  =  (rat2real(a)  +  rat2real(b)/r(2)))
Date html generated:
2019_10_31-AM-05_57_28
Last ObjectModification:
2019_10_30-PM-02_56_59
Theory : reals
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