Nuprl Lemma : fdl-1-join-irreducible
∀[X:Type]
  ∀x,y:Point(free-dl(X)).  (x ∨ y = 1 ∈ Point(free-dl(X)) ⇐⇒ (x = 1 ∈ Point(free-dl(X))) ∨ (y = 1 ∈ Point(free-dl(X))))
Proof
Definitions occuring in Statement : 
free-dl: free-dl(X), 
lattice-1: 1, 
lattice-join: a ∨ b, 
lattice-point: Point(l), 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
or: P ∨ Q, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
member: t ∈ T, 
prop: ℙ, 
subtype_rel: A ⊆r B, 
bdd-distributive-lattice: BoundedDistributiveLattice, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
uimplies: b supposing a, 
rev_implies: P ⇐ Q, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
bfalse: ff, 
exists: ∃x:A. B[x], 
or: P ∨ Q, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
ifthenelse: if b then t else f fi , 
assert: ↑b, 
false: False, 
not: ¬A, 
lattice-point: Point(l), 
record-select: r.x, 
free-dl: free-dl(X), 
mk-bounded-distributive-lattice: mk-bounded-distributive-lattice, 
mk-bounded-lattice: mk-bounded-lattice(T;m;j;z;o), 
record-update: r[x := v], 
eq_atom: x =a y, 
free-dl-type: free-dl-type(X), 
quotient: x,y:A//B[x; y], 
lattice-join: a ∨ b, 
so_lambda: λ2x y.t[x; y], 
free-dl-join: free-dl-join(as;bs), 
append: as @ bs, 
list_ind: list_ind, 
so_apply: x[s1;s2], 
fdl-is-1: fdl-is-1(x)
Lemmas referenced : 
equal_wf, 
lattice-point_wf, 
free-dl_wf, 
subtype_rel_set, 
bounded-lattice-structure_wf, 
lattice-structure_wf, 
lattice-axioms_wf, 
bounded-lattice-structure-subtype, 
bounded-lattice-axioms_wf, 
uall_wf, 
lattice-meet_wf, 
lattice-join_wf, 
lattice-1_wf, 
bdd-distributive-lattice_wf, 
or_wf, 
fdl-is-1_wf, 
bool_wf, 
eqtt_to_assert, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
fdl-eq-1, 
free-dl-type_wf, 
not_wf, 
assert_wf, 
equal-wf-base, 
list_wf, 
dlattice-eq_wf, 
subtype_quotient, 
dlattice-eq-equiv, 
bl-exists_wf, 
append_wf, 
isaxiom_wf_list, 
l_member_wf, 
assert-bl-exists, 
l_exists_append, 
l_exists_wf, 
assert_witness, 
lattice_properties, 
bdd-distributive-lattice-subtype-lattice
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
independent_pairFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
applyEquality, 
sqequalRule, 
instantiate, 
lambdaEquality, 
productEquality, 
cumulativity, 
because_Cache, 
independent_isectElimination, 
setElimination, 
rename, 
universeEquality, 
unionElimination, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
productElimination, 
dependent_pairFormation, 
promote_hyp, 
dependent_functionElimination, 
independent_functionElimination, 
voidElimination, 
inlFormation, 
inrFormation, 
pointwiseFunctionalityForEquality, 
functionEquality, 
hyp_replacement, 
pertypeElimination, 
setEquality, 
addLevel, 
levelHypothesis, 
impliesFunctionality, 
impliesLevelFunctionality, 
applyLambdaEquality
Latex:
\mforall{}[X:Type].  \mforall{}x,y:Point(free-dl(X)).    (x  \mvee{}  y  =  1  \mLeftarrow{}{}\mRightarrow{}  (x  =  1)  \mvee{}  (y  =  1))
Date html generated:
2018_05_22-PM-09_54_40
Last ObjectModification:
2018_05_20-PM-10_11_34
Theory : lattices
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