Given the task definition and input, reply with output. In this task, you will be presented with a context from an academic paper and a question separated with a
. You have to answer the question based on the context.

We evaluate three models of the image attention mechanism INLINEFORM0 of equation EQREF11 . Soft attention Hard Stochastic attention Local Attention
Question: Which attention mechanisms do they compare?
Soft attention Hard Stochastic attention Local Attention