Nuprl Lemma : div-search-lemma
∀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 : 
lelt: i ≤ j < k, 
sq_stable: SqStable(P), 
squash: ↓T, 
guard: {T}, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
cand: A c∧ B, 
so_lambda: λ2x y.t[x; y], 
so_apply: x[s1;s2], 
le: A ≤ B, 
less_than': less_than'(a;b), 
false: False, 
not: ¬A, 
implies: P ⇒ Q, 
subtype_rel: A ⊆r B, 
decidable: Dec(P), 
or: P ∨ Q, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
uiff: uiff(P;Q), 
subtract: n - m, 
top: Top, 
true: True, 
all: ∀x:A. B[x], 
uimplies: b supposing a, 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
int_upper: {i...}, 
so_lambda: λ2x.t[x], 
prop: ℙ, 
and: P ∧ Q, 
int_seg: {i..j-}, 
so_apply: x[s], 
sq_exists: ∃x:A [B[x]]
Lemmas referenced : 
sq_stable__and, 
sq_stable__all, 
sq_stable__not, 
sq_stable_from_decidable, 
decidable__assert, 
assert_witness, 
istype-assert, 
int_seg_properties, 
int_upper_properties, 
full-omega-unsat, 
intformnot_wf, 
intformle_wf, 
itermVar_wf, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf, 
decidable__lt, 
intformand_wf, 
intformless_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_less_lemma, 
itermAdd_wf, 
itermConstant_wf, 
int_term_value_add_lemma, 
int_term_value_constant_lemma, 
divide-and-conquer, 
isect_wf, 
istype-false, 
istype-le, 
member-less_than, 
istype-less_than, 
upper_subtype_upper, 
decidable__le, 
not-le-2, 
condition-implies-le, 
minus-add, 
istype-void, 
minus-one-mul, 
add-swap, 
minus-one-mul-top, 
add-mul-special, 
zero-mul, 
add-zero, 
add-associates, 
add-commutes, 
le-add-cancel, 
sq_exists_wf, 
int_seg_wf, 
all_wf, 
not_wf, 
assert_wf, 
bool_wf, 
istype-int_upper, 
istype-int
Rules used in proof : 
Error :inrFormation_alt, 
promote_hyp, 
Error :inlFormation_alt, 
Error :isectIsType, 
Error :dependent_set_memberFormation_alt, 
Error :functionIsTypeImplies, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
approximateComputation, 
Error :dependent_pairFormation_alt, 
int_eqEquality, 
dependent_functionElimination, 
Error :dependent_set_memberEquality_alt, 
independent_pairFormation, 
independent_functionElimination, 
productElimination, 
independent_pairEquality, 
independent_isectElimination, 
Error :productIsType, 
unionElimination, 
voidElimination, 
Error :isect_memberEquality_alt, 
minusEquality, 
multiplyEquality, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :lambdaFormation_alt, 
Error :isect_memberFormation_alt, 
Error :universeIsType, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
setElimination, 
rename, 
hypothesis, 
sqequalRule, 
Error :lambdaEquality_alt, 
productEquality, 
addEquality, 
because_Cache, 
closedConclusion, 
natural_numberEquality, 
applyEquality, 
Error :functionIsType, 
Error :inhabitedIsType
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-02_12_35
 Last ObjectModification: 
2019_06_20-PM-02_08_48
Theory : int_2
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