> I could probably talk for days about all the different ways every subject can be reduced to transformations and invariants and how they are used to solve prob

> I could probably talk for days about all the different ways every subject can be reduced to transformations and invariants and how they are used to solve problems. I find myself partial to this type of world view too. I believe it is part of the appeal of functional programming, at the basest level, to shape the programming model into transformations (functions) and invariants (state).