Nuprl Lemma : rneq-rabs
∀a,v:ℝ.  (v ≠ a 
⇒ -(v) ≠ a 
⇒ v ≠ |a|)
Proof
Definitions occuring in Statement : 
rneq: x ≠ y
, 
rabs: |x|
, 
rminus: -(x)
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
rneq: x ≠ y
, 
or: P ∨ Q
, 
uimplies: b supposing a
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
cand: A c∧ B
, 
guard: {T}
, 
uiff: uiff(P;Q)
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
not: ¬A
, 
top: Top
, 
squash: ↓T
, 
true: True
, 
subtype_rel: A ⊆r B
, 
less_than: a < b
, 
less_than': less_than'(a;b)
, 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
rneq_wf, 
rminus_wf, 
real_wf, 
rabs_wf, 
rless_wf, 
rneq_functionality, 
req_weakening, 
rabs-of-nonneg, 
zero-rleq-rabs, 
rabs-rless-iff, 
rless-implies-rless, 
rless_transitivity2, 
int-to-real_wf, 
rleq_weakening_rless, 
rsub_wf, 
itermSubtract_wf, 
itermVar_wf, 
itermMinus_wf, 
req-iff-rsub-is-0, 
real_polynomial_null, 
real_term_value_sub_lemma, 
real_term_value_var_lemma, 
real_term_value_minus_lemma, 
real_term_value_const_lemma, 
squash_wf, 
true_wf, 
rminus-rminus-eq, 
iff_weakening_equal, 
rless_transitivity1, 
rmul_reverses_rless_iff, 
rless-int, 
rless_functionality, 
rmul_wf, 
rmul-zero-both, 
itermMultiply_wf, 
itermConstant_wf, 
real_term_value_mul_lemma, 
rabs-of-nonpos, 
rmul_reverses_rless, 
rmul_reverses_rleq_iff, 
rleq_functionality
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
unionElimination, 
because_Cache, 
inlFormation, 
dependent_functionElimination, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
independent_pairFormation, 
natural_numberEquality, 
sqequalRule, 
approximateComputation, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
applyEquality, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
minusEquality, 
inrFormation
Latex:
\mforall{}a,v:\mBbbR{}.    (v  \mneq{}  a  {}\mRightarrow{}  -(v)  \mneq{}  a  {}\mRightarrow{}  v  \mneq{}  |a|)
Date html generated:
2017_10_03-AM-08_39_36
Last ObjectModification:
2017_06_20-AM-11_39_19
Theory : reals
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