Nuprl Lemma : divide-and-conquer-ext

∀[Q:a:ℤ ⟶ {a...} ⟶ ℙ]
  ∀s:{2...}
    ((∀a:ℤ. ∀b:{a..a + s-}.  Q[a;b])
    ⇒ (∀a,b,c:ℤ.  (Q[a;c] ⇒ Q[a;b]) ∨ (Q[c;b] ⇒ Q[a;b]) supposing a < c ∧ c < b)
    ⇒ (∀a:ℤ. ∀b:{a...}.  Q[a;b]))


Proof




Definitions occuring in Statement :  int_upper: {i...},  int_seg: {i..j-},  less_than: a < b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s1;s2],  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q,  and: P ∧ Q,  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,  divide-and-conquer,  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 :  divide-and-conquer,  lifting-strict-decide,  istype-void,  strict4-decide,  lifting-strict-less,  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{}[Q:a:\mBbbZ{}  {}\mrightarrow{}  \{a...\}  {}\mrightarrow{}  \mBbbP{}]
    \mforall{}s:\{2...\}
        ((\mforall{}a:\mBbbZ{}.  \mforall{}b:\{a..a  +  s\msupminus{}\}.    Q[a;b])
        {}\mRightarrow{}  (\mforall{}a,b,c:\mBbbZ{}.    (Q[a;c]  {}\mRightarrow{}  Q[a;b])  \mvee{}  (Q[c;b]  {}\mRightarrow{}  Q[a;b])  supposing  a  <  c  \mwedge{}  c  <  b)
        {}\mRightarrow{}  (\mforall{}a:\mBbbZ{}.  \mforall{}b:\{a...\}.    Q[a;b]))



Date html generated: 2019_06_20-PM-01_15_43
Last ObjectModification: 2019_03_12-PM-09_29_39

Theory : int_2


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