Recursive Data Types in Setl: Automatic Determination, Data Language Description, and Efficient Implementation

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The semantic level of a programming language is characterized by the degree to which a programmer must pay attention to implementation details: the higher level the language, the less need be supplied and the more natural the expressibn of the algorithm. In order to facili tate the natural expression of algorithms, many high level languages free the programmer from the burden of statically typing program variables through declarative statements. In addition, data types far removed from those actually implementable via the hardware are pro vided, again to mask questions of implementation. Thus, compare the classical concordance program written in pl/i, where table handling is the programmer's responsibility, and in.