Expand internal representation of an Attribute to represent idea of absence

[grigoryk]

Expand internal representation of an Attribute to represent idea of absence

[rnewman]

Rule 1 assumes that every attribute must be named by ident. In general we discourage retracting idents (it's kinda scary and meaningless to reassign an ident to a different entity), so…

Rule 2: it would be risky to retract the ident, and bear in mind that you can just retract a single attribute and then assert a new value for it in the same transaction…

What you're talking about here is a kind of consistency: that given a set of schema-required attributes A, this badly written predicate logic holds:

∀ a ∈ A, s ∙ asserted(s, a, _) ⇒ ∀ a' ∈ A ∙ asserted(s, a', _)

In english: for all entities in the union of the domains of required schema attributes, every required schema attribute is present on each entity. You might benefit from thinking about it in those terms.