Streett automata

the acceptance condition is a set $α = {< α_{1}, β_{1} >, \dots, < α_{k}, β_{k} >}$ , where $α_{i}, β_{i} \subseteq Q$

a run is accepting iff for all $α_{i}, β_{i} \subseteq Q$ , $in f (r) \cap α_{i} = \emptyset$ and $in f (r) \cap β_{i} \neq = \emptyset$