Category:Definitions/Summations

This category contains definitions related to Summations.
Related results can be found in Category:Summations.

Let $\map R j$ be a propositional function of $j$.

Then we can write the summation as:

$\ds \sum_{\map R j} a_j = \text{ The sum of all $a_j$ such that $\map R j$ holds}$.

If more than one propositional function is written under the summation sign, they must all hold.