Joseki of the week 6

This week looks at a 3-3 invasion joseki.
After white approaches the 4-4 stone, black plays a high one space extension.

If white can’t make a profitable position on the left,
then preventing black from gaining the corner territory is a possible strategy.
This may occur when stones on the left side are low and black already has, or can easilly reduce any framework white builds.

Black 7(f18) is essential to solidify his influence when there are black stones nearby on the top side.
White is still not completely alive in the corner.
White can play a(d17) directly, poke at b(e16) first and then live with a(d17) to leave a cutting point at c(f15).

If black plans to focus on the top side, then the above can be played.
Black is left with a thick wall and sente, while white retains access to the left side.