Really like an example brought up by<a class="mention" href="/@xliu">@xliu</a> of<a class="mention" href="/@scrypt">@scrypt</a> regarding parent-child relationships in BitCoin: inputs: 0 thru 99 inputs each with 5,000 satoshis each (totalling 500,000 sats) outputs: 0) 249,750 sats to Abigail for services rendered. 1) 249,750 sats to Bertha for services rendered. REMAINDER = 500 sats which becomes part of the block&#39;s coinbase-- mined for the benefit of the winning Node. Question: in the great "chain of digital signatures" story, who is Abigail&#39;s UTXO parents? Which inputs are Bertha&#39;s parents? Are many-input transactions an indirect way to SLIGHTLY wash/cloud the path of coin-travel? When a spent transaction is pruned, other than the branch hash (which could over time rise up to be just the root hash if all the tranactions are spent), what evidence do we have of that transaction at all? Are Nodes keeping just the state of UTXOs, or does BitCoin really have a transaction history which stretches thru all of time? Feel free NOT to answer these questions, but these come to mind when thinking about the protocol and it&#39;s future variability-- ESPECIALLY wrt pruning (which I think is terribly important in the long run, for BitCoin and perhaps one of it&#39;s most elegant features).