There are several "operators" available:
  pattern matching:
        |       or
        &       and
        ~       and-not
  special pattern matching:
        ^       match start
        =       exact match
  pass 1 scan operators:
        #       remark
        "       output to stderr
        '       output to stdout
  response operators:
        1-9     weights are the numerals.
        %       include the rest of the response.
 
Some special notes:
        #,',",weights, and the first ( must be in column one.

Syntax of a simple pattern match:

( A | B & C ~ ( D | E | F))

The above would mean if A or B and C and-not D or E or F was in the
sentence then pick one of the responses.

The responses take on the form:

9this is most likely
4somewhat likely
1least likely

However, when a response is triggered, its weight is decreased by one.
 

Since the above makes little sense, an example will illustrate the use of
Chat databases better.

#!/usr/bin/chat
#change the above line if the chat executable is in a different place.
#an example of a "Chat" database
"this will be printed to stderr
'this will be printed to stdout

(apple & ( orange | lemon ) ~ pine cones)
9You must have a citrus fruit and an apple.
3you do not have a pine cone but you have an apple.
2what was % suppose to mean?

(=your sentence matches this one exactly)
2you are unimaginative.
9you lack imagination.