"form" -> "forms"

[kingdonb]

per #29 (comment) in:

• Best effort internal review using readily available accessible language guides #29

(This looks like a typo to me)

[scottrigby]

I believe this is correct: "the aggregate… forms its desired state…" because aggregate is a singular noun here.

Instead of "forms" though, we could say "comprises" if it feels more clear.

Or better yet, remove all of this redundancy since this is a glossary definition:

- for a system form its desired state which is defined as data 

so it just becomes something like this?:

+ The aggregate of all configuration data that is sufficient to recreate the system so that instances of the system are behaviourally indistinguishable.