t) counts 3. E.g. the tiles in the radius of a city are those with a distance of 5 or less to the city tile.
</p>

<p>
Map locations (represented by the struct Location) and relative coordinates (represented by the struct RC) allow a vector arithmetic:
</p>

<ul>
<li>
Location - Location = RC
</li>
<li>
Location + RC = Location (might be invalid!)
</li>
<li>
Location - RC = Location (might be invalid!)
</li>
<li>
RC + RC = RC
</li>
<li>
RC - RC = RC
</li>
</ul>

<p>
Examples:
</p>
<ul>
<li>
(location1 - loc