The present invention provides settable compositions that comprise water and cement kiln dust. Particularly, propylene polymers can be obtain in very high yields while retaining high stereoregularity. The fetch packets from the instruction memory are parsed into execute packets and sorted by execution unit in a datapath shared by both execution modes. The second sample stream is equalized to generate a second equalized sample stream. The second tab extends along the second side edge of the support panel from the back edge only partially toward the front edge.