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LO7 MINIMUM DISTINGUISHED
Up:
Propositional Logic
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LO5 MINIMUM 3DNF
-
I
NSTANCE
:
Disjoint sets
X,Z
of variables, collection
C
of disjunctive clauses of
at most 3 literals, where a literal is a variable or a negated variable in
.
-
S
OLUTION
:
Truth assignment for
X
and
Z
that satisfies every clause in
C
.
-
M
EASURE
:
The number of
Z
variables that are set to true in the assignment.
-
Bad News:
NPO PB-complete [
200
].
-
Comment:
Transformation from M
AXIMUM
N
UMBER
OF
S
ATISFIABLE
F
ORMULAS
[
281
].
Not approximable within
for any
[
197
].
M
AXIMUM
O
NES
, the variation in which all variables are distinguished,
i.e.
, is also NPO PB-complete [
200
],
and is not approximable within
for any
[
197
].
M
AXIMUM
W
EIGHTED
S
ATISFIABILITY
, the weighted version, in which every variable is assigned
a nonnegative weight, is NPO-complete
[
28
].
Viggo Kann
Mon Apr 21 13:07:14 MET DST 1997