An interval σ is a finite sequence of states
σ : σ0σ1σ2…
Let Σ+ denote the set of all finite intervals with at least 1 state.
The length of an interval σ is denoted by |σ| and is the number of states minus 1.
Let σ = σ0σ1σ2…σ|σ| be an interval then
Let σ = σ0σ1σ2σ3 be an interval then
σ0σ1 |
is a prefix interval of σ |
σ1σ2σ3 | is a suffix interval of σ |
σ1σ2 |
is a sub interval of σ |