Clips rules and functions

Question

Hi, I have several questions:

1. Can I modify a fact in a function in clips or can I use a fact without giving it as a parameter to the call of the function.
2. Can I generate a random number in a rule?
3. Can I execute a certain rule in another rule?
4. Can I make pattern matching in functions?

Answer 1

1. You can modify it with (modify <fact-specifier> <RHS-slot>*)
2. Yes, with function (random [<start-integer-expression> <end-integer-expression>]). Also commendable to set the seed before
3. As far as i know, you can't. Rules are only fired from the agenda
4. You can check if a fact exists with (fact-existp <fact-address-or-index>)