>>52
S = (1+1/3-1/2) + (1/5+1/7-1/4) + (1/9+1/11-1/6) + …
log(2) = (1-1/2+1/3-1/4) + (1/5-1/6+1/7-1/8) + (1/9-1/10+1/11-1/12) + …

S - log(2) = (1/4) + (1/6+1/8-1/4) + (1/10+1/12-1/6) + …
= (1/4) + (1/6-1/8) + (1/10-1/12) + (1/14-1/16) + …
= (1/2)(1/2 + 1/3 - 1/4 + 1/5 - 1/6 + 1/7 - 1/8 + …)
= (1/2)(1 - 1/2 + 1/3 - 1/4 + 1/5 - 1/6 + 1/7 - 1/8 + …)
= (1/2)log(2)