plicit indication of the content of the cited equation, and m a n y pages include a dozen or more such references, often from previous chapters. Each chapter of the book is concluded with sections of exercises, open questions, unsolved problems and c o m m e n t a r y . The preface indicates t h a t the exercises contain problems of "varying difficulty," and m a n y are diiticult or at least technically involved. T h e hints provided in t h e back axe su~icient for the more routine exercises, but often consist solely of references to the literature for the more di~icult problems, which the author admits "amount to small research problems" i n t e n d e d to "present diverse results but without proofs." [page ~ ] The c o m m e n t a r y of each chapter seeks to place the results of the chapter in context, relating it to the historical development of t h e proof, unsuccessful a t t e m p t s and partial results which came along the way a n d further developments and applications of the
/lp/association-for-computing-machinery/lambda-calculi-a-guide-for-computer-scientists-by-chris-hankin-Y1tzpyjwvG