You have first cousins, second cousins, cousins thrice removed that share a common ancestor through one family line. You can even be a first cousin, as well as a second cousin, to the same person depending on the different family lines connections. But I'm curious about what we call our ancestors.
If you have an ancestor that is connected to your family lineage multiple times, through different lines, is there a special designation for that relationship?
Random Eg your paternal greatx7 father is the same man as your maternal greatx7 father. Or paternal greatx7 father is the same man as your maternal greatx7 father AND maternal mother's greatx7 father. The examples go on and on (and don't forget about the more incestuous relationships).
Are they your great X 7 father X 3? Third degree? Raised to the third?
More simply. Brother and sister marry. Your dad is your partners dad and any kids you have will have the same grandfather twice. Aunt marries nephew. You dad is you partners grandfather and any kids you have will have the same man as both their grandfather and great grandfather.
And what happens when there is a generation mismatch: when the common ancestor is in generation 7 in one line and generation 8 in another?
CLARIFICATION EDIT: the answers so far have provided very helpful information, unfortunately not exactly what I was asking. Maybe I muddled up my written question.
I'm not asking how to describe the exact lineage of an ancestor eg John Smith is your mother's father's fathers mothers fathers mothers mothers father. Looking at the answers provided, that seems to be pretty well documented with numerous different systems that all have their pros and cons (some very interesting ideas out there).
I investigating if there is a simple notation I can add to a relative's name/ family designator to say they connect to 2, or 3 or more lines. I can then choose to look in more detail at that persons notes etc to figure out the exact different relationships. This would reduce the number of detailed lineage abbreviations I would have to add to the end of some ancestors entries on my tree, if they connect multiple times.
I have attempted to answer my own question. Please have a look.