Nuprl Lemma : face_lattice-fset-join-eq-1
∀I:fset(ℕ). ∀s:fset(Point(face_lattice(I))).
  (\/(s) = 1 ∈ Point(face_lattice(I)) 
⇐⇒ ∃x:Point(face_lattice(I)). (x ∈ s ∧ (x = 1 ∈ Point(face_lattice(I)))))
Proof
Definitions occuring in Statement : 
face_lattice-deq: face_lattice-deq()
, 
face_lattice: face_lattice(I)
, 
lattice-fset-join: \/(s)
, 
lattice-1: 1
, 
lattice-point: Point(l)
, 
fset-member: a ∈ s
, 
fset: fset(T)
, 
nat: ℕ
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
bdd-distributive-lattice: BoundedDistributiveLattice
, 
so_lambda: λ2x.t[x]
, 
prop: ℙ
, 
and: P ∧ Q
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
implies: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
not: ¬A
, 
false: False
, 
guard: {T}
, 
exists: ∃x:A. B[x]
, 
squash: ↓T
, 
true: True
, 
cand: A c∧ B
, 
sq_stable: SqStable(P)
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
empty-fset: {}
, 
lattice-fset-join: \/(s)
, 
top: Top
, 
fset-add: fset-add(eq;x;s)
, 
uiff: uiff(P;Q)
Lemmas referenced : 
fset-induction, 
lattice-point_wf, 
face_lattice_wf, 
subtype_rel_set, 
bounded-lattice-structure_wf, 
lattice-structure_wf, 
lattice-axioms_wf, 
bounded-lattice-structure-subtype, 
bounded-lattice-axioms_wf, 
uall_wf, 
equal_wf, 
lattice-meet_wf, 
lattice-join_wf, 
face_lattice-deq_wf, 
iff_wf, 
lattice-fset-join_wf, 
decidable__equal_face_lattice, 
lattice-1_wf, 
bdd-distributive-lattice_wf, 
exists_wf, 
fset-member_wf, 
fset_wf, 
sq_stable__iff, 
sq_stable__equal, 
empty-fset_wf, 
fset-add_wf, 
not_wf, 
nat_wf, 
squash_wf, 
true_wf, 
deq_wf, 
iff_weakening_equal, 
decidable__fset-member, 
face-lattice-0-not-1, 
reduce_nil_lemma, 
member-empty-fset, 
bdd-distributive-lattice-subtype-bdd-lattice, 
fset-singleton_wf, 
face_lattice-1-join-irreducible, 
lattice-fset-join-union, 
lattice-fset-join-singleton, 
fset-union_wf, 
member-fset-union, 
member-fset-singleton, 
or_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
applyEquality, 
sqequalRule, 
instantiate, 
lambdaEquality, 
productEquality, 
cumulativity, 
universeEquality, 
because_Cache, 
independent_isectElimination, 
dependent_functionElimination, 
independent_functionElimination, 
setElimination, 
rename, 
independent_pairFormation, 
isect_memberFormation, 
voidElimination, 
productElimination, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
equalityUniverse, 
levelHypothesis, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
dependent_pairFormation, 
unionElimination, 
isect_memberEquality, 
voidEquality, 
inlFormation, 
inrFormation, 
addLevel, 
orFunctionality, 
promote_hyp
Latex:
\mforall{}I:fset(\mBbbN{}).  \mforall{}s:fset(Point(face\_lattice(I))).
    (\mbackslash{}/(s)  =  1  \mLeftarrow{}{}\mRightarrow{}  \mexists{}x:Point(face\_lattice(I)).  (x  \mmember{}  s  \mwedge{}  (x  =  1)))
Date html generated:
2017_10_05-AM-01_10_15
Last ObjectModification:
2017_03_02-PM-10_27_18
Theory : cubical!type!theory
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