Nuprl Lemma : qless-qavg-iff-1
∀[a,b:ℚ].  uiff(a < qavg(a;b);a < b)
Proof
Definitions occuring in Statement : 
qavg: qavg(a;b), 
qless: r < s, 
rationals: ℚ, 
uiff: uiff(P;Q), 
uall: ∀[x:A]. B[x]
Definitions unfolded in proof : 
qavg: qavg(a;b), 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
implies: P ⇒ Q, 
subtype_rel: A ⊆r B, 
not: ¬A, 
qeq: qeq(r;s), 
callbyvalueall: callbyvalueall, 
evalall: evalall(t), 
ifthenelse: if b then t else f fi , 
btrue: tt, 
eq_int: (i =z j), 
bfalse: ff, 
assert: ↑b, 
false: False, 
prop: ℙ, 
qless: r < s, 
grp_lt: a < b, 
set_lt: a <p b, 
set_blt: a <b b, 
band: p ∧b q, 
infix_ap: x f y, 
set_le: ≤b, 
pi2: snd(t), 
oset_of_ocmon: g↓oset, 
dset_of_mon: g↓set, 
grp_le: ≤b, 
pi1: fst(t), 
qadd_grp: <ℚ+>, 
q_le: q_le(r;s), 
bor: p ∨bq, 
qpositive: qpositive(r), 
qsub: r - s, 
qadd: r + s, 
qmul: r * s, 
lt_int: i <z j, 
bnot: ¬bb, 
true: True, 
squash: ↓T, 
guard: {T}, 
iff: P ⇐⇒ Q, 
rev_uimplies: rev_uimplies(P;Q), 
rev_implies: P ⇐ Q
Lemmas referenced : 
qless_witness, 
qless_wf, 
qdiv_wf, 
qadd_wf, 
assert-qeq, 
rationals_wf, 
qmul_preserves_qless, 
qmul_wf, 
squash_wf, 
true_wf, 
int-subtype-rationals, 
qmul-qdiv-cancel, 
subtype_rel_self, 
iff_weakening_equal, 
uiff_transitivity2, 
qadd_preserves_qless, 
qadd_ac_1_q, 
qadd_inv_assoc_q, 
q_distrib, 
qmul_one_qrng
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation_alt, 
introduction, 
cut, 
independent_pairFormation, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
independent_functionElimination, 
hypothesis, 
universeIsType, 
natural_numberEquality, 
applyEquality, 
because_Cache, 
independent_isectElimination, 
lambdaFormation_alt, 
equalityTransitivity, 
equalitySymmetry, 
productElimination, 
voidElimination, 
equalityIstype, 
inhabitedIsType, 
baseClosed, 
sqequalBase, 
independent_pairEquality, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
lambdaEquality_alt, 
imageElimination, 
imageMemberEquality, 
instantiate, 
universeEquality, 
minusEquality
Latex:
\mforall{}[a,b:\mBbbQ{}].    uiff(a  <  qavg(a;b);a  <  b)
Date html generated:
2020_05_20-AM-09_17_10
Last ObjectModification:
2019_11_01-PM-01_55_31
Theory : rationals
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