I need help with a pattern instruction
Please help me read this pattern.I am knitting a Double Breasted Vest from Lion Brand's free patterns. It is s st with a seed stitch edge. I have finished the back and started the left front but now I am totally confused by the following instruction for the Left Front--
V-neck shaping: Next row (RS) Work in St st to last 5 sts, ssk,
work 3 sts in Seed st.
Next row (WS) Slip 1 st, work 2 sts in Seed st, purl to end. Repeat
decs 16 (16, 17, 17, 18, 18) times at neck edge, alternating every
third and fourth rows. Note Dec will be on both RS and WS rows. AT
SAME TIME, continue as before until piece measures 13 (12½, 12, 12½,
12, 12)" from beg, end after a WS
I understand that the decrease that is being repeated (16 times for sz
small) is formed by this instruction:
Next row (RS) Work in St st to last 5 sts, ssk, work 3 sts in Seed st.
I have completed that row and the one that follows which does not
Next row (WS) Slip 1 st, work 2 sts in Seed st, purl to end.
And then I am lost. I asked Lion Brand and their answer is "You are alternating between every 3rd and 4th row; that therefore means you will alternately be on the RS and the WS. Alternating every 3rd and 4th row means 3, 7, 10, 14, etc.These are odd and even rows so you are alternating RS and WS as well.Just be sure you work the decrease at the neck edge."
I'm still confused. My question is - alternating WHAT every 3rd and 4th row and how can you be on both AT SAME TIME and continue exactly WHAT as before until 13"? Can someone please reword this set of instructions, please, please. Thanks!