This is the fourth movement of this string quartet, and is a
combination of a sonata and a rondo. The rondo form is A-B-A-C-A-D-
A, and the sonata-allegro form is exposition, development, and
recapitulation (A B A). The form of this sonata-rondo is A-B-A-C-A-
B-A. The A and B themes act like the two themes of the sonataallegro
form and the C takes the place of the development. This
combination of forms was a common structure used as a climax of
the four-movement structure of a string quartet.
Beethoven does not simply state the themes. Notice how they
always have a sense of development as they return each time.