Nuprl Lemma : rsqrt-positive-iff
∀x:{x:ℝ| r0 ≤ x} . (r0 < rsqrt(x) 
⇐⇒ r0 < x)
Proof
Definitions occuring in Statement : 
rsqrt: rsqrt(x)
, 
rleq: x ≤ y
, 
rless: x < y
, 
int-to-real: r(n)
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
set: {x:A| B[x]} 
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
uimplies: b supposing a
, 
nat_plus: ℕ+
, 
rless: x < y
, 
sq_exists: ∃x:A [B[x]]
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
top: Top
, 
false: False
, 
nat: ℕ
Lemmas referenced : 
rless_wf, 
int-to-real_wf, 
rsqrt_wf, 
rsqrt-positive, 
real_wf, 
rleq_wf, 
rnexp-rless, 
rleq_weakening_equal, 
nat_plus_properties, 
decidable__lt, 
full-omega-unsat, 
intformnot_wf, 
intformless_wf, 
itermConstant_wf, 
istype-int, 
int_formula_prop_not_lemma, 
istype-void, 
int_formula_prop_less_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_wf, 
istype-less_than, 
rnexp_wf, 
decidable__le, 
intformle_wf, 
int_formula_prop_le_lemma, 
istype-le, 
rless_functionality, 
req_weakening, 
rsqrt-rnexp-2, 
rnexp0
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
independent_pairFormation, 
universeIsType, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
natural_numberEquality, 
hypothesis, 
hypothesisEquality, 
applyEquality, 
lambdaEquality_alt, 
setElimination, 
rename, 
inhabitedIsType, 
equalityTransitivity, 
equalitySymmetry, 
sqequalRule, 
dependent_functionElimination, 
dependent_set_memberEquality_alt, 
setIsType, 
because_Cache, 
independent_functionElimination, 
independent_isectElimination, 
unionElimination, 
approximateComputation, 
dependent_pairFormation_alt, 
isect_memberEquality_alt, 
voidElimination, 
productElimination
Latex:
\mforall{}x:\{x:\mBbbR{}|  r0  \mleq{}  x\}  .  (r0  <  rsqrt(x)  \mLeftarrow{}{}\mRightarrow{}  r0  <  x)
Date html generated:
2019_10_30-AM-07_57_40
Last ObjectModification:
2019_03_20-PM-00_31_33
Theory : reals
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