Notice that the line starts with a :- and ends with a period. This is accomplished with the following line: :. The first thing to do is to load your KB. Which is the first line in the Prolog program? The ones that I use are: –goal: This is basically to help prolog determine the exit code of the program. A full listing of the options is available online at.

Swi-prolog allows you to compile using the same command that you use tostart up the interactive interpreter. What’s the best way to compile Prolog program? seen Closes any selected input port/file, and causes ‘read’ to look at user. Subsequent input for ‘read’ is then taken from that port. Then satisfying ‘told’ closes the file and the association of the port or stream with the file. Subsequent writing goes to that file via the port or stream. This one does the rounding, and allows trailing zeroes, but I can find no way to force right alignment using the 'format' function, and I can't find a way to combine the functionality of writef (alignment) with format (rounding and zero display).When Prolog satisfies ‘tell(ToFile)’ the file name bound to ‘ToFile’ will be opened (if it exists) or created and an output port or stream will be associated with the file. Also, I have to do the rounding manually before passing the rounded value to writef().

^^^ This comes very close to what I want, but unfortunately it does display any trailing zeroes (it will always omit them). I can accomplish some of these things individually, but not all at once. For example: 2.500 (trailing zeroes displayed)ģ4.432 (rounded from a much longer decimal value)Īll 3 are right aligned in a 7 character wide space, with 3 decimal places displayed (even when those are zero). My desire is to be able to format numbers that are output such that I am controlling total # decimal digits displayed and also right aligning the numbers in a given character width. I have spent a significant amount of time in the SWI-Prolog documentation and am getting nowhere.

Prolog write