Nuprl Lemma : div-search-lemma-ext

∀a:ℤ. ∀b:{a + 1...}. ∀f:ℤ ⟶ 𝔹.
  ∃x:{a..b-} [((∀y:{a..x + 1-}. (¬↑(f y))) ∧ (∀z:{x + 1..b + 1-}. (↑(f z))))] 
  supposing ∃x:{a..b-} [((∀y:{a..x + 1-}. (¬↑(f y))) ∧ (∀z:{x + 1..b + 1-}. (↑(f z))))]


Proof




Definitions occuring in Statement :  int_upper: {i...},  int_seg: {i..j-},  assert: ↑b,  bool: 𝔹,  uimplies: b supposing a,  all: ∀x:A. B[x],  sq_exists: ∃x:A [B[x]],  not: ¬A,  and: P ∧ Q,  apply: f a,  function: x:A ⟶ B[x],  add: n + m,  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  member: t ∈ T,  subtract: n - m,  genrec-ap: genrec-ap,  ifthenelse: if b then t else f fi ,  div-search-lemma,  divide-and-conquer,  decidable__assert,  uniform-comp-nat-induction,  decidable__lt,  decidable__squash,  decidable__and,  decidable__less_than',  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 :  div-search-lemma,  lifting-strict-decide,  istype-void,  strict4-decide,  lifting-strict-less,  divide-and-conquer,  decidable__assert,  uniform-comp-nat-induction,  decidable__lt,  decidable__squash,  decidable__and,  decidable__less_than',  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{}a:\mBbbZ{}.  \mforall{}b:\{a  +  1...\}.  \mforall{}f:\mBbbZ{}  {}\mrightarrow{}  \mBbbB{}.
    \mexists{}x:\{a..b\msupminus{}\}  [((\mforall{}y:\{a..x  +  1\msupminus{}\}.  (\mneg{}\muparrow{}(f  y)))  \mwedge{}  (\mforall{}z:\{x  +  1..b  +  1\msupminus{}\}.  (\muparrow{}(f  z))))] 
    supposing  \mexists{}x:\{a..b\msupminus{}\}  [((\mforall{}y:\{a..x  +  1\msupminus{}\}.  (\mneg{}\muparrow{}(f  y)))  \mwedge{}  (\mforall{}z:\{x  +  1..b  +  1\msupminus{}\}.  (\muparrow{}(f  z))))]



Date html generated: 2019_06_20-PM-01_15_56
Last ObjectModification: 2019_03_12-PM-09_04_30

Theory : int_2


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