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: 2018_05_21-PM-07_50_38
Last ObjectModification: 2018_05_19-PM-04_49_29

Theory : general


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