The Quintus library contains more than 2MB of source code

Quintus Prolog Libraries

The Quintus Prolog libraries contain over 2MB of Prolog and C source code and documentation. The library files export over 1200 predicates, which you may use in your programs. The library files define over 200 interfaces to C functions and standard system library routines. The Prolog source code in the library files
contains definitions of more than 3000 Prolog predicates, with extensive documentation.

Exported predicates include:

predicates for manipulating Prolog terms and C/C++ data structures,
predicates for arrays, graphs, heaps, lists, queues, search trees, text, and so on,
predicates for operating on files,
interfaces to system libraries, and
predicates for obtaining input, from simple yes/no questions to parsing English sentences.