synth: fix code that depended on iterable numbers.
synth: fix code that depended on iterable numbers.

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