4.2.2 Choice of the way continuation with weighting parameters

The choice of the way continuation happens to ants algorithm based on the marking strengths and the distances between the knots. These are provided with weighting parameters $\alpha$ and $\beta$ which must be chosen reasonably. We define the length between a city i and a city j as $l_{ij}$.
$allowedK$ is the set of all non attendet cities. The probability $p$ that a agent walk from city $i$ to city $j$ can compute as follows:

$$p_{ij} = \frac { \tau_{ij}^\alpha * (\frac{1}{l_{ij}})^\beta}{N}$$

$$N = \sum_{k \epsilon allowedK} \tau_{ik}^\alpha * (\frac{1}{l_{ik}})^\beta$$