MST
2007
13 years 11 months ago
2007
We construct a finite language L such that the largest language commuting with L is not recursively enumerable. This gives a negative answer to the question raised by Conway in 1...
JCT
2007
13 years 11 months ago
2007
In [1] Johnson, Robertson, Seymour and Thomas define the notion of directed tree-width dtw(D) of a directed graph D. They ask whether dtw(D) ≥ k − 1 implies that D has a have...
APPROX
2004
Springer
14 years 4 months ago
2004
Springer
In standard property testing, the task is to distinguish between objects that have a property P and those that are ε-far from P, for some ε > 0. In this setting, it is perfec...