When the last stitch before the edge has been knitted, pull the 4 stitches back, this time knit 3, slip 1 stitch knitwise (part of corner), pull the 4 stitches back, knit 3, slip 1 stitch knitwise, knit 1 and pass the slipped stitch over, back with stitch, 3 knit, slip 1 stitch knitwise (part of corner). *Knit 3, slip 1 stitch knitwise, knit 1 and pass the slipped stitch over*.