Nuprl Lemma : integer-nth-root-ext

∀n:ℕ+. ∀x:ℕ.  (∃r:ℕ [((r^n ≤ x) ∧ x < (r + 1)^n)])


Proof




Definitions occuring in Statement :  exp: i^n,  nat_plus: ℕ+,  nat: ℕ,  less_than: a < b,  le: A ≤ B,  all: ∀x:A. B[x],  sq_exists: ∃x:A [B[x]],  and: P ∧ Q,  add: n + m,  natural_number: $n
Definitions unfolded in proof :  member: t ∈ T,  so_apply: x[s1;s2],  natrec: natrec,  genrec: genrec,  genrec-ap: genrec-ap,  integer-nth-root,  div_nat_induction,  rem_bounds_1,  decidable__lt,  decidable__equal_int,  decidable__squash,  decidable__and,  decidable__less_than',  decidable__int_equal,  decidable_functionality,  squash_elim,  sq_stable_from_decidable,  any: any x,  iff_preserves_decidability,  sq_stable__from_stable,  stable__from_decidable,  uall: ∀[x:A]. B[x],  so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]),  so_apply: x[s1;s2;s3;s4],  so_lambda: λ2x.t[x],  top: Top,  so_apply: x[s],  uimplies: b supposing a
Lemmas referenced :  integer-nth-root,  lifting-strict-int_eq,  istype-void,  strict4-decide,  lifting-strict-decide,  lifting-strict-less,  div_nat_induction,  rem_bounds_1,  decidable__lt,  decidable__equal_int,  decidable__squash,  decidable__and,  decidable__less_than',  decidable__int_equal,  decidable_functionality,  squash_elim,  sq_stable_from_decidable,  iff_preserves_decidability,  sq_stable__from_stable,  stable__from_decidable
Rules used in proof :  introduction,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  cut,  instantiate,  extract_by_obid,  hypothesis,  sqequalRule,  thin,  sqequalHypSubstitution,  equalityTransitivity,  equalitySymmetry,  isectElimination,  baseClosed,  Error :isect_memberEquality_alt,  voidElimination,  independent_isectElimination

Latex:
\mforall{}n:\mBbbN{}\msupplus{}.  \mforall{}x:\mBbbN{}.    (\mexists{}r:\mBbbN{}  [((r\^{}n  \mleq{}  x)  \mwedge{}  x  <  (r  +  1)\^{}n)])



Date html generated: 2019_06_20-PM-02_33_42
Last ObjectModification: 2019_04_15-PM-10_31_53

Theory : num_thy_1


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