Nuprl Lemma : exists-type-equating-ints
∀x,y,n,m:ℤ.
  ((¬(x = y ∈ ℤ))
  
⇒ (¬(n = m ∈ ℤ))
  
⇒ (¬(x = m ∈ ℤ))
  
⇒ (¬(y = n ∈ ℤ))
  
⇒ (∃T:Type. ((x = n ∈ T) ∧ (y = m ∈ T) ∧ (¬(x = y ∈ T)))))
Proof
Definitions occuring in Statement : 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
int: ℤ
, 
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]
, 
subtype_rel: A ⊆r B
, 
exists: ∃x:A. B[x]
, 
or: P ∨ Q
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
uimplies: b supposing a
, 
and: P ∧ Q
, 
b-union: A ⋃ B
, 
tunion: ⋃x:A.B[x]
, 
ifthenelse: if b then t else f fi 
, 
btrue: tt
, 
decidable: Dec(P)
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
false: False
, 
not: ¬A
, 
top: Top
, 
guard: {T}
, 
true: True
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
uiff: uiff(P;Q)
, 
bfalse: ff
, 
sq_type: SQType(T)
, 
bnot: ¬bb
, 
assert: ↑b
, 
pi2: snd(t)
, 
cand: A c∧ B
, 
quotient: x,y:A//B[x; y]
, 
squash: ↓T
Lemmas referenced : 
not_wf, 
equal-wf-base, 
int_subtype_base, 
b-union_wf, 
quotient_wf, 
or_wf, 
true_wf, 
equiv_rel_true, 
btrue_wf, 
quotient-member-eq, 
decidable__equal_int, 
satisfiable-full-omega-tt, 
intformnot_wf, 
intformeq_wf, 
itermVar_wf, 
int_formula_prop_not_lemma, 
int_formula_prop_eq_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf, 
bool_wf, 
eqtt_to_assert, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
bfalse_wf, 
b-union-equality-disjoint, 
isect2_wf, 
isect2_decomp, 
false_wf, 
intformand_wf, 
int_formula_prop_and_lemma
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
intEquality, 
hypothesisEquality, 
applyEquality, 
hypothesis, 
sqequalRule, 
dependent_pairFormation, 
setEquality, 
because_Cache, 
lambdaEquality, 
setElimination, 
rename, 
independent_isectElimination, 
independent_pairFormation, 
productEquality, 
imageMemberEquality, 
dependent_pairEquality, 
dependent_functionElimination, 
dependent_set_memberEquality, 
inlFormation, 
unionElimination, 
natural_numberEquality, 
int_eqEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
inrFormation, 
independent_functionElimination, 
equalityElimination, 
productElimination, 
equalityTransitivity, 
equalitySymmetry, 
promote_hyp, 
instantiate, 
cumulativity, 
baseClosed, 
pointwiseFunctionality, 
pertypeElimination, 
applyLambdaEquality, 
imageElimination
Latex:
\mforall{}x,y,n,m:\mBbbZ{}.
    ((\mneg{}(x  =  y))
    {}\mRightarrow{}  (\mneg{}(n  =  m))
    {}\mRightarrow{}  (\mneg{}(x  =  m))
    {}\mRightarrow{}  (\mneg{}(y  =  n))
    {}\mRightarrow{}  (\mexists{}T:Type.  ((x  =  n)  \mwedge{}  (y  =  m)  \mwedge{}  (\mneg{}(x  =  y)))))
Date html generated:
2017_10_01-AM-09_07_31
Last ObjectModification:
2017_07_26-PM-04_46_48
Theory : general
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