programming-for-dummies

72
Artificial Intelligence Languages
A Prolog program can actually create additional facts (and delete old facts)
while it’s running, so it can appear to think. That’s why Prolog is commonly
used in the field of artificial intelligence. The whole idea behind artificial
intelligence is to make computers smarter and literally think for themselves.
(That’s because computer scientists have pretty much given up hope that
people will ever get smarter or begin to think for themselves.)
Just as knowing two or more human languages can help you better understand
how people communicate, so can knowing two or more different programming
languages help you better understand how programming can
work. The key is to figure out two different programming languages, like C++
and Prolog. Knowing two similar programming languages, like C++ and C#,
doesn’t show you much of a difference.
One of the most popular programming languages favored by the artificial
intelligence community is LISP (which stands for LISt Processing). The basic
idea behind LISP is that everything is a list that can be manipulated by the
computer. For example, a typical LISP command might look like this:
(print “Hello world”)
This LISP command is a list that displays the following on-screen:
“Hello world”
The enclosing parentheses define the start and end of a list. A different way
to print “Hello world” on-screen would be to use this LISP command:
(list “Hello world”)
The preceding command would print the following:
(“Hello world”)
In this case, the list command tells the computer to treat “Hello world”
as a list, so it encloses it in parentheses. Now consider what happens if you
insert a command (list) inside another command (list):
(list (print “Hello world”))
This is how the preceding LISP command works:
1. The innermost command (list) runs first, which is the (print “Hello
world”) list. This displays the following on-screen:
“Hello world”