Nuprl Lemma : qabs-positive-iff
∀[r:ℚ]. uiff(¬(r = 0 ∈ ℚ);0 < |r|)
Proof
Definitions occuring in Statement : 
qabs: |r|
, 
qless: r < s
, 
rationals: ℚ
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
not: ¬A
, 
natural_number: $n
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
not: ¬A
, 
false: False
, 
qless: r < s
, 
grp_lt: a < b
, 
set_lt: a <p b
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
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)
, 
callbyvalueall: callbyvalueall, 
evalall: evalall(t)
, 
qabs: |r|
, 
qpositive: qpositive(r)
, 
btrue: tt
, 
lt_int: i <z j
, 
bfalse: ff
, 
qmul: r * s
, 
bor: p ∨bq
, 
qsub: r - s
, 
qadd: r + s
, 
qeq: qeq(r;s)
, 
eq_int: (i =z j)
, 
bnot: ¬bb
Lemmas referenced : 
qless_witness, 
int-subtype-rationals, 
qabs_wf, 
not_wf, 
equal-wf-T-base, 
rationals_wf, 
qless_wf, 
qabs-positive
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
natural_numberEquality, 
hypothesis, 
applyEquality, 
sqequalRule, 
hypothesisEquality, 
independent_functionElimination, 
baseClosed, 
lambdaFormation, 
voidElimination, 
because_Cache, 
lambdaEquality, 
dependent_functionElimination, 
productElimination, 
independent_pairEquality, 
isect_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
hyp_replacement, 
Error :applyLambdaEquality
Latex:
\mforall{}[r:\mBbbQ{}].  uiff(\mneg{}(r  =  0);0  <  |r|)
Date html generated:
2016_10_25-PM-00_05_11
Last ObjectModification:
2016_07_12-AM-07_49_13
Theory : rationals
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