if file exists…

Maybe a silly question but how do you write a rule such as; "if file exists: do not copy file".
How do you insert a specific "if" in a rule, not the "if All, etc."?

Thank you

I don't quite understand your example, but if you are referring to nested conditions, hold down option which will change the + button. Check the manual on nested conditions for more info.

Not exactly.
Say I have a rule that creates an alias in a specific folder if the document is new.
What I had is that for each recurse Hazel created tons of alias of the same document because every time it saw it as new.
I need to tell it to run the rule once and stop if an alias of the master doc is already there

You should do something like add a tag to the file to indicate that it has already been processed. That, or move the file to another location so that Hazel doesn't have to scan it again.