Row1: k2, sl, k1, psso, knit to last 2sts, K2tog
Row2: purl to last 4 sts, P2togtbl, P2
It seems that the beginning of row 1 and the end of row 2 are the raglan edge.
Decrease at the raglan edge on every row, so rows 1,2,3,4,5,6,7,8 etc. Dec at the front edge on rows 3 and then rows 7, 11, 15, 19, 23, 27 etc until the pattern tells you to stop.
I’ve interpreted the pattern so that the front edge decreases fall on odd number rows.