Nuprl Lemma : ravg_wf
∀[x,y:ℝ].  (ravg(x;y) ∈ ℝ)
Proof
Definitions occuring in Statement : 
ravg: ravg(x;y)
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
ravg: ravg(x;y)
, 
uimplies: b supposing a
, 
rneq: x ≠ y
, 
guard: {T}
, 
or: P ∨ Q
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
, 
less_than: a < b
, 
squash: ↓T
, 
less_than': less_than'(a;b)
, 
true: True
, 
prop: ℙ
Lemmas referenced : 
real_wf, 
rless_wf, 
rless-int, 
int-to-real_wf, 
radd_wf, 
rdiv_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
natural_numberEquality, 
independent_isectElimination, 
inrFormation, 
dependent_functionElimination, 
because_Cache, 
productElimination, 
independent_functionElimination, 
independent_pairFormation, 
imageMemberEquality, 
baseClosed, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
isect_memberEquality
Latex:
\mforall{}[x,y:\mBbbR{}].    (ravg(x;y)  \mmember{}  \mBbbR{})
Date html generated:
2016_05_18-AM-07_34_52
Last ObjectModification:
2016_01_17-AM-02_01_49
Theory : reals
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