<!ELEMENT pingus-level 
        (global,background,(liquid|entrance|exit|groundpiece|trap|hotspot|group)*)>

<!ELEMENT global (author,levelname+,description+,number-of-pingus,number-to-save,time,width,height)>
        <!ELEMENT levelname (#PCDATA)>
                <!ATTLIST levelname          
                        xml:lang CDATA #REQUIRED>
        <!ELEMENT description (#PCDATA)>
                <!ATTLIST description          
                        xml:lang CDATA #REQUIRED>
        <!ELEMENT author (#PCDATA)>
        <!ELEMENT number-of-pingus (#PCDATA)>
        <!ELEMENT number-to-save (#PCDATA)>
        <!ELEMENT time (#PCDATA)>
        <!ELEMENT width (#PCDATA)>
        <!ELEMENT height (#PCDATA)>

<!ELEMENT group (liquid|entrance|exit|groundpiece|trap|hotspot|group)*>

<!ELEMENT surface (resource)>
        <!ELEMENT resource (resource-file|(resource-datafile,resource-ident))>
                <!ATTLIST resource          
                        type CDATA #REQUIRED>
        <!ELEMENT resource-file (#PCDATA)>
        <!ELEMENT resource-datafile (#PCDATA)>
        <!ELEMENT resource-ident (#PCDATA)>

<!ELEMENT position (x-pos,y-pos,z-pos)>
        <!ELEMENT x-pos (#PCDATA)>
        <!ELEMENT y-pos (#PCDATA)>
        <!ELEMENT z-pos (#PCDATA)>

<!ELEMENT background (surface,alpha,red,green,blue,scroll-x,scroll-y,para-x,para-y,stretch-x,stretch-y)>
        <!ELEMENT alpha (#PCDATA)>
        <!ELEMENT red (#PCDATA)>
        <!ELEMENT green (#PCDATA)>
        <!ELEMENT blue (#PCDATA)>
        <!ELEMENT scroll-x (#PCDATA)>
        <!ELEMENT scroll-y (#PCDATA)>
        <!ELEMENT para-x (#PCDATA)>
        <!ELEMENT para-y (#PCDATA)>
        <!ELEMENT stretch-x (#PCDATA)>
        <!ELEMENT stretch-y (#PCDATA)>

<!ELEMENT liquid (surface,position,width,speed)>
        <!ELEMENT speed (#PCDATA)>

<!ELEMENT hotspot (surface,position,speed,para)>
        <!ELEMENT para (#PCDATA)>

<!ELEMENT trap (type,position)>
        <!ELEMENT type (#PCDATA)>

<!ELEMENT exit (position,surface)>

<!ELEMENT entrance (position,type,direction,release-rate)>
        <!ELEMENT direction (#PCDATA)>
        <!ELEMENT release-rate (#PCDATA)>

<!ELEMENT groundpiece (surface, position)>
        <!ATTLIST groundpiece          
                type CDATA #REQUIRED>
<!-- EOF -->