Well-Quasi-Ordering Finite Posets and Formal Languages
Abstract
We show that the set of finite posets is a well-quasi-ordering with respect to a certain relation ≤ called chainminor relation. To prove this we introduce a similar relation on finite formal languages which also has this property. As a consequence we get that every property which is hereditary with respect to ≤ has a polynomial test. This test works also on a parallel machine where it runs in constant time with the same costs.