Positive SSL
A Yb=9邊, Yf=11邊
B Yb=11邊, Yf=9邊
C Yb=11邊, Yf=11邊
D Yb=9邊, Yf=9邊

Yb=Ns/P=21/4=5槽(取整數)

Yc=`(Ns±m)/(P/2)`=(21+1)/(4/2)=11(片) ps:波繞 前進繞+m;後退繞-m。片=槽

Yc=Yb+Yf

Yf=11-5=6槽

Yb'=2Yb+1=5×2+1=11邊

Yf'=2Yf-1=6×2-1=11邊