How to make armhole?

I try to make cache-coeur from Phildar France.
And the translation for shaping armhole is binding off 1 x 3sts, 3 x 2 sts, 4 x 1 sts…anyone know the meaning???

My guess would be bind of 3 stitches on the first row, bind off 2 stitches on the next 3 rows, bind off 1 stitch on the next 4 rows.

HOWEVER, you can only bind off at the beginning of the rows, so you’ll have to do it every other row.