I'd like to make a tiny point on "recursiveness"/self-reference that might suggest it isn't a particularly troublesome feature, in accordance, I believe, with SelfAdjoint's first comment.
Consider the equation:
x=2x-12 (having the solution x=12)
Now, we MIGHT regard this equation as defining "x as the number equal to twice itself minus twelve", i.e, containing a self-reference of some sort.
Furthermore, we can see that in a simple manner, this could lead to a seemingly endless chain of more complicated self-references:
Since x=2x-12, we evidently must have:
x=2(2x-12)-12=2(2(2x-12)-12)-12=2(2(2(2x-12)-12)-12)-12 and so on.
Despite this atrocious behaviour, it is in this case easy to remove the self-referencing definition of x, if that is what one might wish for.
This was probably off-topic..