Nuprl Lemma : qavg-same
∀[a:ℚ]. (qavg(a;a) = a ∈ ℚ)
Proof
Definitions occuring in Statement : 
qavg: qavg(a;b), 
rationals: ℚ, 
uall: ∀[x:A]. B[x], 
equal: s = t ∈ T
Definitions unfolded in proof : 
rev_implies: P ⇐ Q, 
iff: P ⇐⇒ Q, 
guard: {T}, 
qadd: r + s, 
prop: ℙ, 
squash: ↓T, 
false: False, 
assert: ↑b, 
bfalse: ff, 
eq_int: (i =z j), 
btrue: tt, 
ifthenelse: if b then t else f fi , 
evalall: evalall(t), 
callbyvalueall: callbyvalueall, 
qeq: qeq(r;s), 
implies: P ⇒ Q, 
not: ¬A, 
true: True, 
rev_uimplies: rev_uimplies(P;Q), 
and: P ∧ Q, 
uiff: uiff(P;Q), 
uimplies: b supposing a, 
subtype_rel: A ⊆r B, 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
qavg: qavg(a;b)
Lemmas referenced : 
iff_weakening_equal, 
subtype_rel_self, 
qmul-qdiv-cancel, 
q_distrib, 
qmul_ident, 
equal-wf-T-base, 
not_wf, 
istype-universe, 
true_wf, 
squash_wf, 
equal_wf, 
qmul_wf, 
assert-qeq, 
int-subtype-rationals, 
rationals_wf, 
qadd_wf, 
qdiv_wf, 
qmul-preserves-eq
Rules used in proof : 
independent_functionElimination, 
imageMemberEquality, 
universeEquality, 
instantiate, 
imageElimination, 
lambdaEquality_alt, 
sqequalBase, 
baseClosed, 
inhabitedIsType, 
equalityIstype, 
voidElimination, 
independent_pairFormation, 
equalitySymmetry, 
equalityTransitivity, 
lambdaFormation_alt, 
universeIsType, 
productElimination, 
independent_isectElimination, 
applyEquality, 
natural_numberEquality, 
hypothesis, 
because_Cache, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
isect_memberFormation_alt, 
computationStep, 
sqequalTransitivity, 
sqequalReflexivity, 
sqequalRule, 
sqequalSubstitution
Latex:
\mforall{}[a:\mBbbQ{}].  (qavg(a;a)  =  a)
Date html generated:
2019_10_29-AM-07_44_25
Last ObjectModification:
2019_10_21-PM-06_47_17
Theory : rationals
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