Nuprl Lemma : bs_tree_lookup_wf
∀[E:Type]. ∀[cmp:comparison(E)]. ∀[x:E]. ∀[tr:ordered_bs_tree(E;cmp)].
  (bs_tree_lookup(cmp;x;tr) ∈ (∃z:E [(((cmp z x) = 0 ∈ ℤ) ∧ z ∈ tr)]) ∨ (↓∀z:E. (z ∈ tr ⇒ (¬((cmp z x) = 0 ∈ ℤ)))))
Proof
Definitions occuring in Statement : 
bs_tree_lookup: bs_tree_lookup(cmp;x;tr), 
ordered_bs_tree: ordered_bs_tree(E;cmp), 
member_bs_tree: x ∈ tr, 
comparison: comparison(T), 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
sq_exists: ∃x:A [B[x]], 
not: ¬A, 
squash: ↓T, 
implies: P ⇒ Q, 
or: P ∨ Q, 
and: P ∧ Q, 
member: t ∈ T, 
apply: f a, 
natural_number: $n, 
int: ℤ, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
ordered_bs_tree: ordered_bs_tree(E;cmp), 
all: ∀x:A. B[x], 
so_lambda: λ2x.t[x], 
implies: P ⇒ Q, 
prop: ℙ, 
and: P ∧ Q, 
comparison: comparison(T), 
so_apply: x[s], 
guard: {T}, 
member_bs_tree: x ∈ tr, 
bs_tree_lookup: bs_tree_lookup(cmp;x;tr), 
bs_tree_ind: bs_tree_ind, 
bst_null: bst_null(), 
false: False, 
bst_leaf: bst_leaf(value), 
exposed-bfalse: exposed-bfalse, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
uimplies: b supposing a, 
ifthenelse: if b then t else f fi , 
cand: A c∧ B, 
bfalse: ff, 
exists: ∃x:A. B[x], 
or: P ∨ Q, 
sq_type: SQType(T), 
bnot: ¬bb, 
assert: ↑b, 
not: ¬A, 
nequal: a ≠ b ∈ T , 
bs_tree_ordered: bs_tree_ordered(E;cmp;tr), 
bst_node: bst_node(left;value;right), 
has-value: (a)↓, 
less_than: a < b, 
less_than': less_than'(a;b), 
top: Top, 
true: True, 
squash: ↓T, 
decidable: Dec(P), 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
subtype_rel: A ⊆r B, 
iff: P ⇐⇒ Q, 
sq_exists: ∃x:A [B[x]]
Lemmas referenced : 
ordered_bs_tree_wf, 
comparison_wf, 
bs_tree-induction, 
bs_tree_ordered_wf, 
bs_tree_lookup_wf1, 
unit_wf2, 
equal-wf-T-base, 
member_bs_tree_wf, 
all_wf, 
not_wf, 
equal_wf, 
bs_tree_wf, 
false_wf, 
bst_null_wf, 
eq_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_eq_int, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
neg_assert_of_eq_int, 
and_wf, 
bst_leaf_wf, 
bst_node_wf, 
value-type-has-value, 
int-value-type, 
lt_int_wf, 
assert_of_lt_int, 
top_wf, 
less_than_wf, 
decidable__equal_int, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformeq_wf, 
itermVar_wf, 
itermConstant_wf, 
intformless_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_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, 
or_wf, 
le_wf, 
itermMinus_wf, 
int_term_value_minus_lemma, 
squash_wf, 
true_wf, 
comparison-anti, 
subtype_rel_self, 
iff_weakening_equal, 
int_subtype_base, 
sq_exists_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
setElimination, 
thin, 
rename, 
hypothesis, 
sqequalRule, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
isect_memberEquality, 
because_Cache, 
dependent_functionElimination, 
universeEquality, 
lambdaEquality, 
functionEquality, 
unionEquality, 
lambdaFormation, 
unionElimination, 
productEquality, 
intEquality, 
applyEquality, 
baseClosed, 
independent_functionElimination, 
voidElimination, 
natural_numberEquality, 
equalityElimination, 
productElimination, 
independent_isectElimination, 
independent_pairFormation, 
dependent_pairFormation, 
promote_hyp, 
instantiate, 
cumulativity, 
dependent_set_memberEquality, 
applyLambdaEquality, 
callbyvalueReduce, 
lessCases, 
axiomSqEquality, 
voidEquality, 
imageMemberEquality, 
imageElimination, 
approximateComputation, 
int_eqEquality, 
inlFormation, 
inrFormation, 
hyp_replacement, 
equalityUniverse, 
levelHypothesis, 
minusEquality, 
inlEquality, 
inrEquality
Latex:
\mforall{}[E:Type].  \mforall{}[cmp:comparison(E)].  \mforall{}[x:E].  \mforall{}[tr:ordered\_bs\_tree(E;cmp)].
    (bs\_tree\_lookup(cmp;x;tr)  \mmember{}  (\mexists{}z:E  [(((cmp  z  x)  =  0)  \mwedge{}  z  \mmember{}  tr)])
      \mvee{}  (\mdownarrow{}\mforall{}z:E.  (z  \mmember{}  tr  {}\mRightarrow{}  (\mneg{}((cmp  z  x)  =  0)))))
Date html generated:
2019_10_15-AM-10_47_54
Last ObjectModification:
2018_08_21-PM-01_58_46
Theory : tree_1
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