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: + nat: less_than: a < b le: A ≤ B all: x:A. B[x] sq_exists: x:A [B[x]] and: P ∧ Q add: m natural_number: $n
Definitions unfolded in proof :  member: t ∈ T integer-nth-root div_nat_induction natrec: natrec genrec: genrec so_apply: x[s1;s2] decidable__equal_int decidable__int_equal 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: supposing a strict4: strict4(F) and: P ∧ Q all: x:A. B[x] implies:  Q has-value: (a)↓ prop: guard: {T} or: P ∨ Q squash: T rem_bounds_1 decidable__lt decidable__squash so_lambda: λ2y.t[x; y] decidable_functionality iff_preserves_decidability decidable__and decidable__less_than' genrec-ap: genrec-ap
Lemmas referenced :  integer-nth-root lifting-strict-int_eq top_wf equal_wf has-value_wf_base base_wf is-exception_wf lifting-strict-spread lifting-strict-decide lifting-strict-less div_nat_induction decidable__equal_int decidable__int_equal rem_bounds_1 decidable__lt decidable__squash decidable_functionality iff_preserves_decidability decidable__and decidable__less_than'
Rules used in proof :  introduction sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity cut instantiate extract_by_obid hypothesis sqequalRule thin sqequalHypSubstitution isectElimination baseClosed isect_memberEquality voidElimination voidEquality independent_isectElimination independent_pairFormation lambdaFormation callbyvalueDecide hypothesisEquality equalityTransitivity equalitySymmetry unionEquality unionElimination sqleReflexivity dependent_functionElimination independent_functionElimination baseApply closedConclusion decideExceptionCases inrFormation because_Cache imageMemberEquality imageElimination exceptionSqequal inlFormation callbyvalueApply applyExceptionCases

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



Date html generated: 2018_05_21-PM-07_50_18
Last ObjectModification: 2017_07_26-PM-05_28_05

Theory : general


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