Nuprl Lemma : rabs-rinv
∀y:ℝ. (y ≠ r0 
⇒ (|rinv(y)| = rinv(|y|)))
Proof
Definitions occuring in Statement : 
rneq: x ≠ y
, 
rabs: |x|
, 
rinv: rinv(x)
, 
req: x = y
, 
int-to-real: r(n)
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
rneq: x ≠ y
, 
or: P ∨ Q
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
itermConstant: "const"
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
not: ¬A
, 
top: Top
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
guard: {T}
, 
rev_uimplies: rev_uimplies(P;Q)
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
Lemmas referenced : 
rabs-neq-zero, 
rneq_wf, 
int-to-real_wf, 
real_wf, 
rless-implies-rless, 
rminus_wf, 
real_term_polynomial, 
itermSubtract_wf, 
itermConstant_wf, 
itermVar_wf, 
itermMinus_wf, 
real_term_value_const_lemma, 
real_term_value_sub_lemma, 
real_term_value_var_lemma, 
real_term_value_minus_lemma, 
req-iff-rsub-is-0, 
rsub_wf, 
rless_wf, 
rabs-of-nonpos, 
rleq_weakening_rless, 
rabs_wf, 
rinv_wf2, 
req_functionality, 
req_weakening, 
rinv_functionality2, 
rmul_reverses_rleq_iff, 
rmul_wf, 
rleq-int, 
false_wf, 
rleq_functionality, 
itermMultiply_wf, 
real_term_value_mul_lemma, 
req_transitivity, 
rmul-rinv, 
rmul_preserves_req, 
rabs-of-nonneg, 
rmul_preserves_rleq
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
independent_functionElimination, 
hypothesis, 
addLevel, 
unionElimination, 
levelHypothesis, 
isectElimination, 
natural_numberEquality, 
inrFormation, 
because_Cache, 
independent_isectElimination, 
sqequalRule, 
computeAll, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
productElimination, 
independent_pairFormation
Latex:
\mforall{}y:\mBbbR{}.  (y  \mneq{}  r0  {}\mRightarrow{}  (|rinv(y)|  =  rinv(|y|)))
Date html generated:
2017_10_03-AM-08_37_35
Last ObjectModification:
2017_07_28-AM-07_30_14
Theory : reals
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