> Consider the whole database - the whole set of facts across all relations - as the state in the tree.
I tried to demonstrate that this is easier said than done. Deciding the equality/redundancy of facts is very subtle. At some it might even be guess whether your two clerks each met the same Alice when entering in their DB forks or not.
Transactions are just patches, I completely agree. And patches are just partial functions. But deciding what the action is of a partial function, or whether the input is in the domain requires a notion of equality. (Partial functions are encoded very nicely with incomplete pattern matching; in this case the question is whether Alice matches the pattern.)
Basically I know where you are coming from, and I want it to work too, but you cannot just wave away the math and issues it points out.)
I tried to demonstrate that this is easier said than done. Deciding the equality/redundancy of facts is very subtle. At some it might even be guess whether your two clerks each met the same Alice when entering in their DB forks or not.
Transactions are just patches, I completely agree. And patches are just partial functions. But deciding what the action is of a partial function, or whether the input is in the domain requires a notion of equality. (Partial functions are encoded very nicely with incomplete pattern matching; in this case the question is whether Alice matches the pattern.)
Basically I know where you are coming from, and I want it to work too, but you cannot just wave away the math and issues it points out.)