>Hi.
Hi, Andres:

>What does the star besides the cursor's arrow mean?

That's the "execute" cursor; it should be displayed whenever an action 
will take longer than a second or so to give feedback to the user.  See 
the Cursor class constants for a list of the cursors available.

>	^self class new: value + (self negated and: aProbability negated) value
>
>an error occurs and a message appears saying that the arguments for #and: 
>have to be either a variable or a block?

I assume that the class this method is in implements an "and:" message, 
which is what you are trying to use in the code above.  Unfortunately, 
"and:" is one of the few messages that cannot be redefined, because it is 
hard-coded in the compiler.  The message you see is reported from the 
compiler when it is performing the transformAnd: Macro Transformation.  
It is checking to see that the argument to and: is either an immediate 
block or a variable that might hold a block.

If this is the case, then you will have to choose a different names for 
your operations than "and:" and "or:".



     -- tim