use dup surround instead of 3append
use dup surround instead of 3append

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