I am discussing an ordered set of all tensors of all orders, which is of course infinite. I need to indicate a placeholder which precedes all members of the set.
Is there a symbol or notation for the element that precedes all other elements of an ordered set?
I am tempted to use –∞ but that is wrong because –∞ is really just another 0th order tensor, and in my specific ordering, there are infinitely many tensors that precede –∞.