add tests for infinite sequence subscripts
add tests for infinite sequence subscripts

cygx/roast,laben/roast,zostay/roast,laben/roast,bitrauser/roast,dogbert17/roast,niner/roast,dankogai/roast,cygx/roast,niner/roast,skids/roast,zostay/roast,dankogai/roast,skids/roast,bitrauser/roast,skids/roast,b2gills/roast,dogbert17/roast,b2gills/roast,zostay/roast,laben/roast,perl6/roast,niner/roast,cygx/roast,b2gills/roast,dankogai/roast