09.12.2012 Views

Concrete mathematics : a foundation for computer science

Concrete mathematics : a foundation for computer science

Concrete mathematics : a foundation for computer science

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

32 SUMS<br />

Typically we use rule (2.20) either to combine two almost-disjoint index sets,<br />

as in<br />

m n n<br />

tak + t ak = am + x ak, <strong>for</strong> 1 < m < n;<br />

k=l k=m k=l<br />

or to split off a single term from a sum, as in<br />

ak = a0 + ak , <strong>for</strong> n 3 0.<br />

O

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!