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This pattern is essentially knit in one piece. You start at the bottom fronts, cast on for the sleeves, shape the neck opening, cast off the sleeves and then knit down the back to the lower edge (top down on the schematic). The only sewing will be the seam at each sleeve and along each side. The directions for the cardigan come partway down the pattern instructions. Instead of casting of for the full front (55sts) You'll be making 2 fronts (34sts each) with separate balls of yarn. It'll probably be easier to knit these fronts at the same time, keeping the yarn balls separate. They'll join up after the neck is complete when you're ready to knit down the back.
So that we don't run into copyright problems, could you edit the pattern so that the complete pattern doesn't appear, pleae?