3-5 point, 4-3 approach, one-space pincer, diagonal, knight's move

Joseki  

is one of the common responses. The most common responses (in order of frequency) are:

• at a: Ikken-tobi
• at b: Attach
• as tenuki

Invasion Joseki  

itself is an uncommon move, but the two choices that appeared were a and b.

Var 1  

here is somewhat forced

Var 2  

Cutting is much more natural, but then serves as a probe and - is exchanged before making life in the corner. However, the stones are separated and White can next seal in the corner with a, so this looks more like an emergency measure by Black than a real joseki.