Nuprl Lemma : per-union-elim
∀[A,B:Type].
  ∀x:per-union(A;B)
    per-or(uand(x ~ inl outl(x);outl(x) ∈ A supposing x ~ inl outl(x));uand(x ~ inr outr(x) outr(x) ∈ B 
                                                                                             supposing x 
                                                                                             ~ inr outr(x) ))
Proof
Definitions occuring in Statement : 
per-union: per-union(A;B)
, 
per-or: per-or(A;B)
, 
uand: uand(A;B)
, 
outr: outr(x)
, 
outl: outl(x)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
inr: inr x 
, 
inl: inl x
, 
universe: Type
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
per-or: per-or(A;B)
, 
per-exists: per-exists(A;a.B[a])
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
uand: uand(A;B)
, 
has-value: (a)↓
, 
top: Top
, 
per-function: per-function(A;a.B[a])
, 
function-eq: function-eq(A;a.B[a];f;g)
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
sq_type: SQType(T)
, 
implies: P 
⇒ Q
, 
guard: {T}
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
per-union: per-union(A;B)
, 
outl: outl(x)
, 
outr: outr(x)
, 
false: False
Lemmas referenced : 
per-union-elim1, 
per-product-elim, 
per-value_wf, 
has-value_wf_base, 
is-exception_wf, 
per-value-property, 
istype-top, 
istype-void, 
per-union_wf, 
istype-universe, 
per-function_wf_type, 
per-value_subtype_base, 
subtype_base_sq, 
base_wf, 
subtype_rel_self, 
per-union-implies-wf1, 
equal_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
per-union-implies-wf2, 
if-per-void, 
uand_wf, 
equal-wf-base, 
per-void_wf, 
member_wf, 
member-per-or-left, 
int_subtype_base, 
istype-base, 
member-per-or-right
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
Error :lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
dependent_functionElimination, 
hypothesis, 
sqequalRule, 
baseClosed, 
axiomSqleEquality, 
divergentSqle, 
sqleReflexivity, 
because_Cache, 
isaxiomCases, 
promote_hyp, 
axiomSqEquality, 
Error :inhabitedIsType, 
Error :isect_memberEquality_alt, 
Error :isectIsTypeImplies, 
voidElimination, 
Error :universeIsType, 
instantiate, 
universeEquality, 
pointwiseFunctionalityForEquality, 
equalityTransitivity, 
equalitySymmetry, 
pertypeMemberEquality, 
Error :equalityIstype, 
sqequalBase, 
axiomEquality, 
baseApply, 
closedConclusion, 
applyEquality, 
cumulativity, 
independent_isectElimination, 
independent_functionElimination, 
functionExtensionality, 
Error :lambdaEquality_alt, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality, 
productElimination, 
pointwiseFunctionality, 
pertypeElimination, 
isinlCases, 
rename, 
isectEquality, 
isinrCases, 
intEquality
Latex:
\mforall{}[A,B:Type].
    \mforall{}x:per-union(A;B)
        per-or(uand(x  \msim{}  inl  outl(x);outl(x)  \mmember{}  A  supposing  x  \msim{}  inl  outl(x));uand(x 
        \msim{}  inr  outr(x)  ;outr(x)  \mmember{}  B  supposing  x  \msim{}  inr  outr(x)  ))
Date html generated:
2019_06_20-AM-11_30_51
Last ObjectModification:
2019_01_22-AM-09_59_22
Theory : per!type
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