Question re Aran pattern

Hi,
Part of the pattern reads: yfsl1 = with yarn in front, slip the (one =) stitch purlwise. The pattern row reads:k1, k1, p3, k1, p1, k1, p4, k1, p2, yfsl1, k1, p2, k1;
How do I knit the pattern without adding ad additional stitch? Thanks Jenny 48

Welcome to KnittingHelp!
Bring the yarn to the back between the needles after you slip one.
So:
k1, k1, p3, k1, p1, k1, p4, k1, p2, yfsl1, [I]yarn to the back, [/I]k1, p2, k1