Nuprl Lemma : fan_theorem
∀[X:n:ℕ ⟶ (ℕn ⟶ 𝔹) ⟶ ℙ]
  (∀n:ℕ. ∀s:ℕn ⟶ 𝔹.  Dec(X[n;s])) 
⇒ (∃k:ℕ. ∀f:ℕ ⟶ 𝔹. ∃n:ℕk. X[n;f]) supposing ∀f:ℕ ⟶ 𝔹. (↓∃n:ℕ. X[n;f])
Proof
Definitions occuring in Statement : 
int_seg: {i..j-}
, 
nat: ℕ
, 
bool: 𝔹
, 
decidable: Dec(P)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
squash: ↓T
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
squash: ↓T
, 
implies: P 
⇒ Q
, 
sq_exists: ∃x:A [B[x]]
, 
nat: ℕ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
exists: ∃x:A. B[x]
, 
ge: i ≥ j 
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
false: False
, 
top: Top
, 
and: P ∧ Q
, 
prop: ℙ
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
so_apply: x[s1;s2]
, 
le: A ≤ B
, 
subtype_rel: A ⊆r B
, 
less_than': less_than'(a;b)
, 
less_than: a < b
, 
outl: outl(x)
Lemmas referenced : 
simple_fan_theorem'-ext, 
set-value-type, 
equal_wf, 
int-value-type, 
nat_properties, 
decidable__le, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
intformeq_wf, 
istype-int, 
int_formula_prop_and_lemma, 
istype-void, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_eq_lemma, 
int_formula_prop_wf, 
istype-le, 
decidable__lt, 
intformless_wf, 
int_formula_prop_less_lemma, 
istype-less_than, 
int_seg_properties, 
int_seg_wf, 
subtype_rel_function, 
nat_wf, 
bool_wf, 
int_seg_subtype_nat, 
istype-false, 
subtype_rel_self, 
istype-nat, 
decidable_wf, 
squash_wf, 
int_seg_decide_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
sqequalRule, 
Error :lambdaEquality_alt, 
dependent_functionElimination, 
imageElimination, 
imageMemberEquality, 
baseClosed, 
Error :functionIsTypeImplies, 
Error :inhabitedIsType, 
rename, 
independent_isectElimination, 
Error :lambdaFormation_alt, 
independent_functionElimination, 
setElimination, 
intEquality, 
cutEval, 
Error :dependent_set_memberEquality_alt, 
equalityTransitivity, 
equalitySymmetry, 
Error :equalityIstype, 
Error :universeIsType, 
Error :dependent_pairFormation_alt, 
natural_numberEquality, 
unionElimination, 
approximateComputation, 
int_eqEquality, 
Error :isect_memberEquality_alt, 
voidElimination, 
independent_pairFormation, 
productElimination, 
Error :productIsType, 
because_Cache, 
applyEquality, 
Error :functionIsType, 
instantiate, 
universeEquality, 
productEquality, 
functionExtensionality, 
functionEquality
Latex:
\mforall{}[X:n:\mBbbN{}  {}\mrightarrow{}  (\mBbbN{}n  {}\mrightarrow{}  \mBbbB{})  {}\mrightarrow{}  \mBbbP{}]
    (\mforall{}n:\mBbbN{}.  \mforall{}s:\mBbbN{}n  {}\mrightarrow{}  \mBbbB{}.    Dec(X[n;s]))  {}\mRightarrow{}  (\mexists{}k:\mBbbN{}.  \mforall{}f:\mBbbN{}  {}\mrightarrow{}  \mBbbB{}.  \mexists{}n:\mBbbN{}k.  X[n;f]) 
    supposing  \mforall{}f:\mBbbN{}  {}\mrightarrow{}  \mBbbB{}.  (\mdownarrow{}\mexists{}n:\mBbbN{}.  X[n;f])
Date html generated:
2019_06_20-PM-01_15_29
Last ObjectModification:
2019_01_27-PM-01_53_25
Theory : int_2
Home
Index