Nuprl Lemma : implies-le-face-lattice-join
∀T:Type. ∀eq:EqDecider(T). ∀x,y,z:Point(face-lattice(T;eq)).
  ((∀s:fset(T + T). (s ∈ z 
⇒ ((↓∃t:fset(T + T). (t ∈ x ∧ t ⊆ s)) ∨ (↓∃t:fset(T + T). (t ∈ y ∧ t ⊆ s))))) 
⇒ z ≤ x ∨ y)
Proof
Definitions occuring in Statement : 
face-lattice: face-lattice(T;eq)
, 
lattice-le: a ≤ b
, 
lattice-join: a ∨ b
, 
lattice-point: Point(l)
, 
deq-fset: deq-fset(eq)
, 
f-subset: xs ⊆ ys
, 
fset-member: a ∈ s
, 
fset: fset(T)
, 
union-deq: union-deq(A;B;a;b)
, 
deq: EqDecider(T)
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
squash: ↓T
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
, 
and: P ∧ Q
, 
union: left + right
, 
universe: Type
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
top: Top
, 
subtype_rel: A ⊆r B
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
and: P ∧ Q
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
uiff: uiff(P;Q)
, 
rev_uimplies: rev_uimplies(P;Q)
, 
uimplies: b supposing a
, 
squash: ↓T
, 
exists: ∃x:A. B[x]
, 
or: P ∨ Q
, 
bdd-distributive-lattice: BoundedDistributiveLattice
, 
face-lattice: face-lattice(T;eq)
, 
fset-constrained-ac-lub: lub(P;ac1;ac2)
, 
cand: A c∧ B
Lemmas referenced : 
subtype_rel_sets, 
fset-ac-lub-covers, 
free-dlwc-join, 
deq_wf, 
lattice-meet_wf, 
equal_wf, 
uall_wf, 
bounded-lattice-axioms_wf, 
bounded-lattice-structure-subtype, 
lattice-axioms_wf, 
lattice-structure_wf, 
bounded-lattice-structure_wf, 
subtype_rel_set, 
lattice-point_wf, 
f-subset_wf, 
exists_wf, 
squash_wf, 
or_wf, 
all_wf, 
deq-fset_wf, 
fset-member_wf, 
ac-covers_wf, 
assert-ac-covers, 
face-lattice_wf, 
lattice-join_wf, 
face-lattice-le, 
face-lattice-constraints_wf, 
fset-contains-none_wf, 
fset-all_wf, 
union-deq_wf, 
fset-antichain_wf, 
assert_wf, 
and_wf, 
fset_wf, 
fl-point-sq
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
sqequalRule, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
hypothesis, 
lambdaEquality, 
setElimination, 
rename, 
hypothesisEquality, 
setEquality, 
unionEquality, 
dependent_functionElimination, 
applyEquality, 
because_Cache, 
productElimination, 
independent_functionElimination, 
introduction, 
independent_pairFormation, 
independent_isectElimination, 
addLevel, 
allFunctionality, 
impliesFunctionality, 
orFunctionality, 
levelHypothesis, 
promote_hyp, 
allLevelFunctionality, 
impliesLevelFunctionality, 
orLevelFunctionality, 
imageElimination, 
imageMemberEquality, 
baseClosed, 
cumulativity, 
functionEquality, 
productEquality, 
instantiate, 
universeEquality
Latex:
\mforall{}T:Type.  \mforall{}eq:EqDecider(T).  \mforall{}x,y,z:Point(face-lattice(T;eq)).
    ((\mforall{}s:fset(T  +  T)
            (s  \mmember{}  z  {}\mRightarrow{}  ((\mdownarrow{}\mexists{}t:fset(T  +  T).  (t  \mmember{}  x  \mwedge{}  t  \msubseteq{}  s))  \mvee{}  (\mdownarrow{}\mexists{}t:fset(T  +  T).  (t  \mmember{}  y  \mwedge{}  t  \msubseteq{}  s)))))
    {}\mRightarrow{}  z  \mleq{}  x  \mvee{}  y)
Date html generated:
2016_05_18-AM-11_41_19
Last ObjectModification:
2016_01_20-PM-10_31_03
Theory : lattices
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