icosphere:
    type: procedure
    debug: false
    definitions: subdivisions
    script:
        - define lookup <map>
        - define verts:->:<static[<location[-1,1.618033988749895,0].normalize>]>
        - define verts:->:<static[<location[1,1.618033988749895,0].normalize>]>
        - define verts:->:<static[<location[-1,-1.618033988749895,0].normalize>]>
        - define verts:->:<static[<location[1,-1.618033988749895,0].normalize>]>
        - define verts:->:<static[<location[0,-1,1.618033988749895].normalize>]>
        - define verts:->:<static[<location[0,1,1.618033988749895].normalize>]>
        - define verts:->:<static[<location[0,-1,-1.618033988749895].normalize>]>
        - define verts:->:<static[<location[0,1,-1.618033988749895].normalize>]>
        - define verts:->:<static[<location[1.618033988749895,0,-1].normalize>]>
        - define verts:->:<static[<location[1.618033988749895,0,1].normalize>]>
        - define verts:->:<static[<location[-1.618033988749895,0,-1].normalize>]>
        - define verts:->:<static[<location[-1.618033988749895,0,1].normalize>]>
        - define faces:->:<static[<list[1|12|6]>]>
        - define faces:->:<static[<list[1|6|2]>]>
        - define faces:->:<static[<list[1|2|8]>]>
        - define faces:->:<static[<list[1|8|11]>]>
        - define faces:->:<static[<list[1|11|12]>]>
        - define faces:->:<static[<list[2|6|10]>]>
        - define faces:->:<static[<list[6|12|5]>]>
        - define faces:->:<static[<list[12|11|3]>]>
        - define faces:->:<static[<list[11|8|7]>]>
        - define faces:->:<static[<list[8|2|9]>]>
        - define faces:->:<static[<list[4|10|5]>]>
        - define faces:->:<static[<list[4|5|3]>]>
        - define faces:->:<static[<list[5|3|7]>]>
        - define faces:->:<static[<list[4|7|9]>]>
        - define faces:->:<static[<list[4|9|10]>]>
        - define faces:->:<static[<list[5|10|6]>]>
        - define faces:->:<static[<list[3|5|12]>]>
        - define faces:->:<static[<list[7|3|11]>]>
        - define faces:->:<static[<list[9|7|8]>]>
        - define faces:->:<static[<list[10|9|2]>]>
        - repeat <[subdivisions]>:
            - define face_subdivisions <list>
            - foreach <[faces]> as:triangle:
                - define new_verts <list>
                - foreach 1,2|2,3|3,1 as:tuple:
                    - define indices <[tuple].split[,]>
                    - define i1 <[triangle].get[<[indices].first>]>
                    - define i2 <[triangle].get[<[indices].last>]>
                    - define min <[i1].min[<[i2]>]>
                    - define max <[i1].max[<[i2]>]>
                    - define key <[min]>_<[max]>
                    - if not <[lookup.<[key]>].exists>:
                        - define verts:->:<proc[midpoint].context[a=<[verts].get[<[min]>]>;b=<[verts].get[<[max]>]>].normalize>
                        - define lookup.<[key]>:<[verts].size>
                    - define new_verts:->:<[lookup.<[key]>]>
                - define face_subdivisions:->:<list[<[triangle].get[1]>|<[new_verts].get[1]>|<[new_verts].get[3]>]>
                - define face_subdivisions:->:<list[<[triangle].get[2]>|<[new_verts].get[2]>|<[new_verts].get[1]>]>
                - define face_subdivisions:->:<list[<[triangle].get[3]>|<[new_verts].get[3]>|<[new_verts].get[2]>]>
                - define face_subdivisions:->:<list[<[new_verts].get[1]>|<[new_verts].get[2]>|<[new_verts].get[3]>]>
            - define faces <[face_subdivisions]>
        - determine <[verts]>