Error: dependency cycles amongst the xpath expressions in relevant/calculate

Hi all,
Could you please help me dealing with this error!
I don't know what is this and could any one please explain why it is?

It means you probably have a logic error in your form somewhere. Could you please post your form, otherwise it’s really not possible to determine where the error exists. Thnx.

Please make sure you have read and understood all of the posts at https://forum.getodk.org/search?q=dependency%20cycles! Once you have, if you still have a question, please be specific about where you think the problem might be when you post the blank form.