Nuprl Lemma : lattice-join-is-lub
∀l:Lattice. ∀a,b:Point(l).  least-upper-bound(Point(l);x,y.x ≤ y;a;b;a ∨ b)
Proof
Definitions occuring in Statement : 
lattice-le: a ≤ b, 
lattice: Lattice, 
lattice-join: a ∨ b, 
lattice-point: Point(l), 
least-upper-bound: least-upper-bound(T;x,y.R[x; y];a;b;c), 
all: ∀x:A. B[x]
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
least-upper-bound: least-upper-bound(T;x,y.R[x; y];a;b;c), 
and: P ∧ Q, 
lattice-le: a ≤ b, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
cand: A c∧ B, 
implies: P ⇒ Q, 
prop: ℙ, 
lattice: Lattice, 
uiff: uiff(P;Q), 
uimplies: b supposing a, 
squash: ↓T, 
true: True, 
subtype_rel: A ⊆r B, 
guard: {T}, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q
Lemmas referenced : 
lattice_properties, 
equal_wf, 
lattice-point_wf, 
lattice-meet_wf, 
lattice_wf, 
lattice-join_wf, 
lattice-le-iff, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
lattice-structure_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
independent_pairFormation, 
equalitySymmetry, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
productElimination, 
hypothesis, 
sqequalRule, 
setElimination, 
rename, 
because_Cache, 
hyp_replacement, 
applyLambdaEquality, 
independent_isectElimination, 
applyEquality, 
lambdaEquality, 
imageElimination, 
equalityTransitivity, 
universeEquality, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_functionElimination
Latex:
\mforall{}l:Lattice.  \mforall{}a,b:Point(l).    least-upper-bound(Point(l);x,y.x  \mleq{}  y;a;b;a  \mvee{}  b)
Date html generated:
2017_10_05-AM-00_31_02
Last ObjectModification:
2017_07_28-AM-09_12_53
Theory : lattices
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