Nuprl Lemma : list_accum_invariant3
∀[T,A:Type].
  ∀f:A ⟶ T ⟶ A
    ∀[P:A ⟶ (T List) ⟶ ℙ]
      ∀L:T List. ∀a:A.
        (P[a;[]]
        
⇒ (∀a:A. ∀x:T. ∀L':T List.  (L' @ [x] ≤ L 
⇒ P[a;L'] 
⇒ P[f[a;x];L' @ [x]]))
        
⇒ P[accumulate (with value a and list item x):
              f[a;x]
             over list:
               L
             with starting value:
              a);L])
Proof
Definitions occuring in Statement : 
iseg: l1 ≤ l2
, 
append: as @ bs
, 
list_accum: list_accum, 
cons: [a / b]
, 
nil: []
, 
list: T List
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
exists: ∃x:A. B[x]
, 
member: t ∈ T
, 
prop: ℙ
, 
nat: ℕ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s1;s2]
, 
subtype_rel: A ⊆r B
, 
so_apply: x[s]
, 
so_lambda: λ2x y.t[x; y]
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
top: Top
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
false: False
, 
squash: ↓T
, 
true: True
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
decidable: Dec(P)
, 
or: P ∨ Q
Lemmas referenced : 
length_wf_nat, 
length_wf, 
equal_wf, 
equal-wf-base-T, 
all_wf, 
list_wf, 
iseg_wf, 
append_wf, 
cons_wf, 
nil_wf, 
int_subtype_base, 
list_accum_wf, 
set_wf, 
less_than_wf, 
primrec-wf2, 
nat_wf, 
length_zero, 
list_accum_nil_lemma, 
last_lemma, 
assert_of_null, 
length_of_nil_lemma, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformeq_wf, 
itermVar_wf, 
itermConstant_wf, 
intformless_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_eq_lemma, 
int_term_value_var_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_wf, 
assert_wf, 
null_wf, 
list_accum_append, 
subtype_rel_list, 
top_wf, 
list_accum_cons_lemma, 
last_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
iseg_weakening, 
iseg_append, 
length-append, 
length_of_cons_lemma, 
decidable__equal_int, 
add-is-int-iff, 
intformnot_wf, 
itermSubtract_wf, 
itermAdd_wf, 
int_formula_prop_not_lemma, 
int_term_value_subtract_lemma, 
int_term_value_add_lemma, 
false_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
dependent_pairFormation, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
cumulativity, 
hypothesisEquality, 
hypothesis, 
intEquality, 
setElimination, 
rename, 
productElimination, 
baseClosed, 
sqequalRule, 
lambdaEquality, 
because_Cache, 
functionEquality, 
applyEquality, 
functionExtensionality, 
baseApply, 
closedConclusion, 
natural_numberEquality, 
dependent_functionElimination, 
independent_functionElimination, 
universeEquality, 
equalitySymmetry, 
independent_isectElimination, 
dependent_set_memberEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
hyp_replacement, 
applyLambdaEquality, 
int_eqEquality, 
independent_pairFormation, 
computeAll, 
imageElimination, 
equalityTransitivity, 
imageMemberEquality, 
equalityUniverse, 
levelHypothesis, 
unionElimination, 
pointwiseFunctionality, 
promote_hyp
Latex:
\mforall{}[T,A:Type].
    \mforall{}f:A  {}\mrightarrow{}  T  {}\mrightarrow{}  A
        \mforall{}[P:A  {}\mrightarrow{}  (T  List)  {}\mrightarrow{}  \mBbbP{}]
            \mforall{}L:T  List.  \mforall{}a:A.
                (P[a;[]]
                {}\mRightarrow{}  (\mforall{}a:A.  \mforall{}x:T.  \mforall{}L':T  List.    (L'  @  [x]  \mleq{}  L  {}\mRightarrow{}  P[a;L']  {}\mRightarrow{}  P[f[a;x];L'  @  [x]]))
                {}\mRightarrow{}  P[accumulate  (with  value  a  and  list  item  x):
                            f[a;x]
                          over  list:
                              L
                          with  starting  value:
                            a);L])
Date html generated:
2017_04_17-AM-07_38_43
Last ObjectModification:
2017_02_27-PM-04_13_27
Theory : list_1
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