sequences.extras: adding a contains? (a faster sequence intersects?).
sequences.extras: adding a contains? (a faster sequence intersects?).

bjourne/factor,tgunr/factor,AlexIljin/factor,sarvex/factor-lang,dch/factor,bjourne/factor,mrjbq7/factor,slavapestov/factor,bpollack/factor,factor/factor,sarvex/factor-lang,nicolas-p/factor,mrjbq7/factor,bjourne/factor,factor/factor,dch/factor,tgunr/factor,slavapestov/factor,sarvex/factor-lang,factor/factor,nicolas-p/factor,bpollack/factor,tgunr/factor,AlexIljin/factor,slavapestov/factor,factor/factor,tgunr/factor,AlexIljin/factor,bpollack/factor,bjourne/factor,dch/factor,dch/factor,slavapestov/factor,bpollack/factor,tgunr/factor,sarvex/factor-lang,dch/factor,bpollack/factor,slavapestov/factor,slavapestov/factor,sarvex/factor-lang,bjourne/factor,bjourne/factor,bjourne/factor,factor/factor,nicolas-p/factor,sarvex/factor-lang,factor/factor,nicolas-p/factor,bpollack/factor,nicolas-p/factor,bpollack/factor,tgunr/factor,AlexIljin/factor,mrjbq7/factor,mrjbq7/factor,AlexIljin/factor,mrjbq7/factor,dch/factor,AlexIljin/factor,nicolas-p/factor,AlexIljin/factor,nicolas-p/factor,mrjbq7/factor,sarvex/factor-lang,slavapestov/factor