2 <!ELEMENT name (#PCDATA)
>
3 <!ELEMENT mass (#PCDATA)
>
4 <!ELEMENT inertia (#PCDATA)
>
5 <!ELEMENT pair (#PCDATA)
>
6 <!ELEMENT radius (#PCDATA)
>
7 <!ELEMENT event (#PCDATA)
>
8 <!ELEMENT script (#PCDATA)
>
10 <!ELEMENT source (#PCDATA)
>
11 <!ELEMENT angle (#PCDATA)
>
14 <!ELEMENT graphics (source, pos)
>
16 <!ELEMENT actor (name, graphics*, physics?, reaction*)
>
18 <!ELEMENT physics ((body, (poly | circle | line)*) | nophysics)
>
20 <!ELEMENT fixed EMPTY
>
21 <!ELEMENT nophysics EMPTY
>
23 <!ELEMENT body (mass, inertia, fixed?)
>
25 <!ELEMENT poly (data, offset, elasticity, friction)
>
26 <!ELEMENT circle (offset, radius, elasticity, friction)
>
27 <!ELEMENT line (pair, pair, radius, elasticity, friction)
>
29 <!ELEMENT elasticity (#PCDATA)
>
30 <!ELEMENT friction (#PCDATA)
>
32 <!ELEMENT data (pair*)
>
33 <!ELEMENT offset (pair*)
>
35 <!ELEMENT reaction (event, script)
>
