don't think about it too hard. you wouldn't want to anger the OP_CAT stans with good critical questions. we could have vaults, don't ya know!

There are a bunch of practical limits you run up against. For example, if you want to introspect an input/output of a previous transaction, that transaction will be limited to something like 6 inputs/outputs. Because we dont have loops, its not practical to have variable length history to validate, etc.

On things like that is very useful is you can stick all the states of your state machine in different tapleafs and just send back to the same script over and over. Thats all it really means that its recursive. Its not scary, you’re just sending back to the same address. Makes some things a lot simpler, makes other things trickier.