Nuprl Lemma : prior-cases
∀[T:Type]
  ∀f:ℕ ⟶ (T + Top). ∀n:ℕ.
    case prior(n;f)
     of inl(p) =>
     let m,x = p 
     in ((f m) = (inl x) ∈ (T + Top)) ∧ (∀k:{m + 1..n-}. (¬↑isl(f k)))
     | inr(q) =>
     ∀k:ℕn. (¬↑isl(f k))
Proof
Definitions occuring in Statement : 
prior: prior(n;f), 
int_seg: {i..j-}, 
nat: ℕ, 
assert: ↑b, 
isl: isl(x), 
uall: ∀[x:A]. B[x], 
top: Top, 
all: ∀x:A. B[x], 
not: ¬A, 
and: P ∧ Q, 
apply: f a, 
function: x:A ⟶ B[x], 
spread: spread def, 
decide: case b of inl(x) => s[x] | inr(y) => t[y], 
inl: inl x, 
union: left + right, 
add: n + m, 
natural_number: $n, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
prior: prior(n;f), 
so_lambda: λ2x y.t[x; y], 
member: t ∈ T, 
top: Top, 
so_apply: x[s1;s2], 
ifthenelse: if b then t else f fi , 
eq_int: (i =z j), 
btrue: tt, 
not: ¬A, 
implies: P ⇒ Q, 
false: False, 
guard: {T}, 
int_seg: {i..j-}, 
lelt: i ≤ j < k, 
and: P ∧ Q, 
uimplies: b supposing a, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
prop: ℙ, 
subtype_rel: A ⊆r B, 
le: A ≤ B, 
less_than': less_than'(a;b), 
nat: ℕ, 
decidable: Dec(P), 
or: P ∨ Q, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
ge: i ≥ j , 
exposed-bfalse: exposed-bfalse, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
uiff: uiff(P;Q), 
bfalse: ff, 
sq_type: SQType(T), 
bnot: ¬bb, 
assert: ↑b, 
has-value: (a)↓, 
cand: A c∧ B, 
isl: isl(x), 
less_than: a < b
Lemmas referenced : 
natrec-unroll, 
int_seg_properties, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformless_wf, 
itermVar_wf, 
itermConstant_wf, 
intformle_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_less_lemma, 
int_term_value_var_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_wf, 
assert_wf, 
isl_wf, 
top_wf, 
nat_wf, 
int_seg_subtype_nat, 
false_wf, 
int_seg_wf, 
prior_wf, 
subtract_wf, 
decidable__le, 
intformnot_wf, 
itermSubtract_wf, 
int_formula_prop_not_lemma, 
int_term_value_subtract_lemma, 
le_wf, 
unit_wf2, 
equal_wf, 
all_wf, 
not_wf, 
itermAdd_wf, 
int_term_value_add_lemma, 
set_wf, 
less_than_wf, 
primrec-wf2, 
nat_properties, 
eq_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_eq_int, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
neg_assert_of_eq_int, 
value-type-has-value, 
int-value-type, 
subtract-add-cancel, 
decidable__lt, 
lelt_wf, 
int_subtype_base, 
decidable__equal_int, 
assert_elim, 
and_wf, 
bfalse_wf, 
btrue_neq_bfalse
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
thin, 
sqequalRule, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
hypothesis, 
natural_numberEquality, 
because_Cache, 
hypothesisEquality, 
setElimination, 
rename, 
productElimination, 
independent_isectElimination, 
dependent_pairFormation, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
dependent_functionElimination, 
independent_pairFormation, 
computeAll, 
independent_functionElimination, 
cumulativity, 
applyEquality, 
functionExtensionality, 
dependent_set_memberEquality, 
unionElimination, 
unionEquality, 
productEquality, 
inlEquality, 
addEquality, 
applyLambdaEquality, 
equalityTransitivity, 
equalitySymmetry, 
functionEquality, 
universeEquality, 
equalityElimination, 
promote_hyp, 
instantiate, 
callbyvalueReduce, 
addLevel, 
levelHypothesis, 
independent_pairEquality, 
axiomEquality
Latex:
\mforall{}[T:Type]
    \mforall{}f:\mBbbN{}  {}\mrightarrow{}  (T  +  Top).  \mforall{}n:\mBbbN{}.
        case  prior(n;f)
          of  inl(p)  =>
          let  m,x  =  p 
          in  ((f  m)  =  (inl  x))  \mwedge{}  (\mforall{}k:\{m  +  1..n\msupminus{}\}.  (\mneg{}\muparrow{}isl(f  k)))
          |  inr(q)  =>
          \mforall{}k:\mBbbN{}n.  (\mneg{}\muparrow{}isl(f  k))
Date html generated:
2017_10_01-AM-09_12_06
Last ObjectModification:
2017_07_26-PM-04_47_53
Theory : general
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