Nuprl Lemma : type-separation
∀x,y:Base.
  (((x)↓ ∨ is-exception(x))
  ⇒ ((y)↓ ∨ is-exception(y))
  ⇒ (∀n,m:ℤ. ∀T:Type.  ((x = n ∈ T) ⇒ (y = m ∈ T) ⇒ (x = y ∈ T)))
  ⇒ (x = y ∈ Base))
Proof
Definitions occuring in Statement : 
has-value: (a)↓, 
is-exception: is-exception(t), 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
or: P ∨ Q, 
int: ℤ, 
base: Base, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
prop: ℙ, 
uall: ∀[x:A]. B[x], 
so_lambda: λ2x.t[x], 
subtype_rel: A ⊆r B, 
so_apply: x[s], 
or: P ∨ Q, 
exists: ∃x:A. B[x], 
and: P ∧ Q, 
cand: A c∧ B, 
true: True, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
uimplies: b supposing a, 
ifthenelse: if b then t else f fi , 
decidable: Dec(P), 
not: ¬A, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
false: False, 
top: Top, 
bfalse: ff, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
assert: ↑b, 
squash: ↓T, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
label: ...$L... t, 
has-value: (a)↓
Lemmas referenced : 
all_wf, 
equal-wf-base, 
int_subtype_base, 
or_wf, 
has-value_wf_base, 
is-exception_wf, 
base_wf, 
has-value-implies-dec-isint, 
imax_wf, 
less_than_wf, 
ifthenelse_wf, 
le_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_le_int, 
decidable__lt, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformless_wf, 
itermVar_wf, 
itermAdd_wf, 
itermConstant_wf, 
intformle_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_less_lemma, 
int_term_value_var_lemma, 
int_term_value_add_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_wf, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
le_wf, 
squash_wf, 
true_wf, 
add_functionality_wrt_eq, 
imax_unfold, 
subtype_rel_self, 
iff_weakening_equal, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
not_wf, 
exists_wf, 
and_wf, 
exception-not-value, 
value-type-has-value, 
int-value-type, 
EquatePairs_wf, 
EquatePairs-equality, 
equal_functionality_wrt_subtype_rel2
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
hypothesis, 
thin, 
instantiate, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
cumulativity, 
intEquality, 
sqequalRule, 
lambdaEquality, 
universeEquality, 
functionEquality, 
hypothesisEquality, 
applyEquality, 
because_Cache, 
unionElimination, 
dependent_functionElimination, 
baseClosed, 
independent_functionElimination, 
dependent_pairFormation, 
addEquality, 
natural_numberEquality, 
independent_pairFormation, 
productEquality, 
equalityTransitivity, 
equalitySymmetry, 
equalityElimination, 
productElimination, 
independent_isectElimination, 
approximateComputation, 
int_eqEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
promote_hyp, 
imageElimination, 
imageMemberEquality, 
baseApply, 
closedConclusion, 
sqequalIntensionalEquality, 
dependent_set_memberEquality, 
applyLambdaEquality, 
setElimination, 
rename, 
isintReduceTrue, 
inrFormation, 
inlFormation
Latex:
\mforall{}x,y:Base.
    (((x)\mdownarrow{}  \mvee{}  is-exception(x))
    {}\mRightarrow{}  ((y)\mdownarrow{}  \mvee{}  is-exception(y))
    {}\mRightarrow{}  (\mforall{}n,m:\mBbbZ{}.  \mforall{}T:Type.    ((x  =  n)  {}\mRightarrow{}  (y  =  m)  {}\mRightarrow{}  (x  =  y)))
    {}\mRightarrow{}  (x  =  y))
Date html generated:
2018_05_21-PM-01_13_20
Last ObjectModification:
2018_05_01-PM-04_37_20
Theory : num_thy_1
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