just googled/bookmarked: http://www.cs.princeton.edu/~dpw/papers/TCS04.pdf http://www.cs.princeton.edu/~dpw/papers/TCS04.pdf http://www.metaocaml.org/concoqti

just googled/bookmarked: http://www.cs.princeton.edu/~dpw/papers/TCS04.pdf http://www.cs.princeton.edu/~dpw/papers/TCS04.pdf http://www.metaocaml.org/concoqtion/techreport.pdf http://www.metaocaml.org/concoqtion/techreport.pdf http://www.cis.upenn.edu/~sweirich/plmw12/Slides/plmw12-Pierce.pdf http://www.cis.upenn.edu/~sweirich/plmw12/Slides/plmw12-Pier... slide 8: summary = impossible