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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