Add empty set as a term.  Not sure how to go on from here, though  :-(
Add empty set as a term.  Not sure how to go on from here, though  :-(

skids/rakudo,usev6/rakudo,nunorc/rakudo,nbrown/rakudo,tony-o/rakudo,nunorc/rakudo,Gnouc/rakudo,rakudo/rakudo,samcv/rakudo,labster/rakudo,nbrown/rakudo,ab5tract/rakudo,dwarring/rakudo,tony-o/deb-rakudodaily,ungrim97/rakudo,tony-o/deb-rakudodaily,raydiak/rakudo,ugexe/rakudo,raydiak/rakudo,b2gills/rakudo,tony-o/deb-rakudodaily,nbrown/rakudo,skids/rakudo,tony-o/rakudo,laben/rakudo,nunorc/rakudo,labster/rakudo,raydiak/rakudo,tbrowder/rakudo,salortiz/rakudo,usev6/rakudo,cygx/rakudo,cognominal/rakudo,awwaiid/rakudo,skids/rakudo,Leont/rakudo,labster/rakudo,raydiak/rakudo,tony-o/rakudo,cygx/rakudo,jonathanstowe/rakudo,usev6/rakudo,azawawi/rakudo,MasterDuke17/rakudo,labster/rakudo,cygx/rakudo,awwaiid/rakudo,teodozjan/rakudo,awwaiid/rakudo,tony-o/rakudo,sjn/rakudo,softmoth/rakudo,sergot/rakudo,sjn/rakudo,MasterDuke17/rakudo,azawawi/rakudo,rakudo/rakudo,niner/rakudo,ugexe/rakudo,Leont/rakudo,tbrowder/rakudo,niner/rakudo,tony-o/rakudo,dankogai/rakudo,tony-o/deb-rakudodaily,dankogai/rakudo,laben/rakudo,retupmoca/rakudo,b2gills/rakudo,salortiz/rakudo,awwaiid/rakudo,ungrim97/rakudo,tony-o/deb-rakudodaily,rakudo/rakudo,zostay/rakudo,salortiz/rakudo,salortiz/rakudo,lucasbuchala/rakudo,ugexe/rakudo,niner/rakudo,lucasbuchala/rakudo,Gnouc/rakudo,tony-o/rakudo,laben/rakudo,MasterDuke17/rakudo,MasterDuke17/rakudo,labster/rakudo,tony-o/deb-rakudodaily,retupmoca/rakudo,paultcochrane/rakudo,ab5tract/rakudo,nunorc/rakudo,azawawi/rakudo,LLFourn/rakudo,ab5tract/rakudo,cognominal/rakudo,retupmoca/rakudo,sjn/rakudo,paultcochrane/rakudo,softmoth/rakudo,labster/rakudo,tbrowder/rakudo,LLFourn/rakudo,skids/rakudo,dankogai/rakudo,sjn/rakudo,teodozjan/rakudo,rakudo/rakudo,dwarring/rakudo,softmoth/rakudo,dankogai/rakudo,lucasbuchala/rakudo,dankogai/rakudo,zhuomingliang/rakudo,samcv/rakudo,salortiz/rakudo,dwarring/rakudo,rakudo/rakudo,cognominal/rakudo,LLFourn/rakudo,nbrown/rakudo,Gnouc/rakudo,cognominal/rakudo,lucasbuchala/rakudo,tbrowder/rakudo,jonathanstowe/rakudo,sergot/rakudo,Gnouc/rakudo,ungrim97/rakudo,softmoth/rakudo,awwaiid/rakudo,MasterDuke17/rakudo,samcv/rakudo,nbrown/rakudo,tony-o/deb-rakudodaily,lucasbuchala/rakudo,ab5tract/rakudo,cygx/rakudo,paultcochrane/rakudo,zostay/rakudo,ungrim97/rakudo,laben/rakudo,ungrim97/rakudo,usev6/rakudo,jonathanstowe/rakudo,azawawi/rakudo,skids/rakudo,b2gills/rakudo,dwarring/rakudo,nbrown/rakudo,ugexe/rakudo,zostay/rakudo,ab5tract/rakudo,tbrowder/rakudo,cognominal/rakudo,salortiz/rakudo,ugexe/rakudo,zhuomingliang/rakudo,LLFourn/rakudo,tbrowder/rakudo,rakudo/rakudo,zhuomingliang/rakudo,zhuomingliang/rakudo,retupmoca/rakudo,sergot/rakudo,LLFourn/rakudo,Gnouc/rakudo,Gnouc/rakudo,azawawi/rakudo,softmoth/rakudo,teodozjan/rakudo,sjn/rakudo,Leont/rakudo,Leont/rakudo,jonathanstowe/rakudo,MasterDuke17/rakudo,paultcochrane/rakudo,paultcochrane/rakudo,usev6/rakudo,sergot/rakudo,cygx/rakudo,teodozjan/rakudo,b2gills/rakudo,zostay/rakudo,b2gills/rakudo,samcv/rakudo,niner/rakudo,jonathanstowe/rakudo,samcv/rakudo