ISO/Edinburgh-style Prolog interpreter

 SWI-Prolog is a fast and powerful ISO/Edinburgh-style Prolog compiler with a
 rich set of built-in predicates. It offers a fast, robust and small
 environment which enables substantial applications to be developed with it.
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 SWI-Prolog additionally offers:
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  * A powerful module system
  * Garbage collection
  * Unicode character set handling
  * Unbounted integer and rational number arithmetic
  * Multithreading support
  * A powerful C/C++ interface
  * GNU Readline interface