Exercises

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Most chapters include extensive exercises—some designed for pencil and paper, some involving programming examples in the calculi under discussion, and some concerning extensions to the ML implementations of these calculi. The estimated difficulty of each exercise is indicated using the following scale:

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  ⋆	Quick check	30 seconds to 5 minutes
  ⋆⋆	Easy	≤ 1 hour
  ⋆⋆⋆	Moderate	≤ 3 hours
  ⋆⋆⋆⋆	Challenging	> 3 hours

Exercises marked ⋆ are intended as real-time checks of important concepts. Readers are strongly encouraged to pause for each one of these before moving on to the material that follows. In each chapter, a roughly homework-assignment-sized set of exercises is labeled RECOMMENDED.

Complete solutions to most of the exercises are provided in Appendix A. To save readers the frustration of searching for solutions to the few exercises for which solutions are not available, those exercises are marked ↛.

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