There is a problem with situation calculus. Suppose the bananas are at c in state s0. Where are the bananas after the monkey pushes the box, in state pushbox(b, c, goto(a, b, s0)) ?
It is necessary to write frame axioms to describe what does not change when each operator is applied. Unfortunately, most things do not change for most operators. Worse, a combinatoric number of axioms is required.
This is an instance of the frame problem[The frame problem is not related to the representational technique of frames, which uses the same word.]: the problem of maintaining a valid world model as some things in the world change.