Nuprl Lemma : qabs-neg
∀[r:ℚ]. (|-(r)| = |r| ∈ ℚ)
Proof
Definitions occuring in Statement : 
qabs: |r|
, 
qmul: r * s
, 
rationals: ℚ
, 
uall: ∀[x:A]. B[x]
, 
minus: -n
, 
natural_number: $n
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
squash: ↓T
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
true: True
, 
uimplies: b supposing a
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
equal_wf, 
squash_wf, 
true_wf, 
rationals_wf, 
qabs-qminus, 
qmul_wf, 
int-subtype-rationals, 
qabs_wf, 
iff_weakening_equal, 
qinv_inv_q
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
cut, 
applyEquality, 
thin, 
lambdaEquality, 
sqequalHypSubstitution, 
imageElimination, 
introduction, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
universeEquality, 
minusEquality, 
natural_numberEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
because_Cache
Latex:
\mforall{}[r:\mBbbQ{}].  (|-(r)|  =  |r|)
Date html generated:
2018_05_21-PM-11_53_41
Last ObjectModification:
2017_07_26-PM-06_45_45
Theory : rationals
Home
Index