Nuprl Lemma : iroot-property
∀[n:ℕ+]. ∀[x:ℕ].  ((iroot(n;x)^n ≤ x) ∧ x < (iroot(n;x) + 1)^n)
Proof
Definitions occuring in Statement : 
iroot: iroot(n;x)
, 
exp: i^n
, 
nat_plus: ℕ+
, 
nat: ℕ
, 
less_than: a < b
, 
uall: ∀[x:A]. B[x]
, 
le: A ≤ B
, 
and: P ∧ Q
, 
add: n + m
, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
iroot: iroot(n;x)
, 
subtype_rel: A ⊆r B
, 
all: ∀x:A. B[x]
, 
so_lambda: λ2x.t[x]
, 
prop: ℙ
, 
and: P ∧ Q
, 
nat: ℕ
, 
so_apply: x[s]
, 
sq_exists: ∃x:A [B[x]]
, 
implies: P 
⇒ Q
, 
le: A ≤ B
, 
not: ¬A
, 
false: False
, 
uimplies: b supposing a
, 
sq_stable: SqStable(P)
, 
squash: ↓T
Lemmas referenced : 
integer-nth-root-ext, 
subtype_rel_self, 
nat_plus_wf, 
all_wf, 
nat_wf, 
sq_exists_wf, 
le_wf, 
exp_wf2, 
less_than_wf, 
equal_wf, 
member-less_than, 
less_than'_wf, 
nat_plus_subtype_nat, 
iroot_wf, 
squash_wf, 
sq_stable__and, 
sq_stable__le, 
sq_stable__less_than
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
applyEquality, 
thin, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
sqequalHypSubstitution, 
isectElimination, 
functionEquality, 
lambdaEquality, 
productEquality, 
hypothesisEquality, 
because_Cache, 
setElimination, 
rename, 
addEquality, 
natural_numberEquality, 
lambdaFormation, 
equalityTransitivity, 
equalitySymmetry, 
dependent_functionElimination, 
independent_functionElimination, 
productElimination, 
independent_pairEquality, 
axiomEquality, 
independent_isectElimination, 
isect_memberEquality, 
voidElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination
Latex:
\mforall{}[n:\mBbbN{}\msupplus{}].  \mforall{}[x:\mBbbN{}].    ((iroot(n;x)\^{}n  \mleq{}  x)  \mwedge{}  x  <  (iroot(n;x)  +  1)\^{}n)
Date html generated:
2019_06_20-PM-02_34_03
Last ObjectModification:
2019_03_19-AM-10_49_16
Theory : num_thy_1
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