Nuprl Lemma : qminus-positive
∀[r:ℚ]. uiff(0 < -(r);r < 0)
Proof
Definitions occuring in Statement : 
qless: r < s
, 
qmul: r * s
, 
rationals: ℚ
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
minus: -n
, 
natural_number: $n
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
, 
guard: {T}
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
rev_uimplies: rev_uimplies(P;Q)
, 
true: True
, 
squash: ↓T
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
iff_weakening_equal, 
mon_ident_q, 
qinverse_q, 
qadd_comm_q, 
qadd_wf, 
rationals_wf, 
qless_wf, 
int-subtype-rationals, 
qless_witness, 
qmul_wf, 
qadd_preserves_qless
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
because_Cache, 
minusEquality, 
natural_numberEquality, 
hypothesis, 
applyEquality, 
sqequalRule, 
hypothesisEquality, 
productElimination, 
independent_isectElimination, 
independent_functionElimination, 
independent_pairEquality, 
isect_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
lambdaEquality, 
imageElimination, 
imageMemberEquality, 
baseClosed
Latex:
\mforall{}[r:\mBbbQ{}].  uiff(0  <  -(r);r  <  0)
Date html generated:
2016_05_15-PM-10_54_41
Last ObjectModification:
2016_01_16-PM-09_34_21
Theory : rationals
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