This is MetaPost, version 1.999 (TeX Live 2015/Debian) (kpathsea version 6.2.1)  3 OCT 2018 23:31
**infinity.mp
(/usr/share/texlive/texmf-dist/metapost/base/mpost.mp
(/usr/share/texlive/texmf-dist/metapost/base/plain.mp
Preloading the plain mem file, version 1.005) ) (./infinity.mp
Path at line 8, before choices:
(0,0){4096,0}
 ..{4096,0}(20,10){4096,0}
 ..{-4096,0}(20,0){-4096,0}
 ..{-4096,0}(0,10){-4096,0}
 ..{4096,0}cycle

Path at line 8, after choices:
(0,0)..controls (7.86894,0) and (12.13106,10)
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 ..(20,0)..controls (12.13106,0) and (7.86894,10)
 ..(0,10)..controls (-6.66667,10) and (-6.66667,0)
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 [1] )
1 output file written: infinity.svg