S = 1-1+1-1+1-1+1-1.....
S = 1-(1-1+1-1+1-1+1-1.....)
S = 1- (S)
S = 1- [1-(S)]
S = 1- {1-[1-(S)]}
..... 我也覺得無意義..


S = 1- (S) 代換過來S=1/2
S = 1- [1-(S)] 代換過來S=S
S = 1- {1-[1-(S)]} 代換過來S=1/2
.............................

不太明白您的無意義點是......................