The Function type really benefits from a dedicated viewer.
Optionally, also have a dedicated editor and creator.
Z8K1/identity, pointing to its own ZID
Z8K2/list of argument declarations
(Z8K3/list of tests - for later)
Z8K4/(list of?) implementation
This also requires an Z17/argument declaration type with an Z17K1/type ID, Z17K2/key, and Z17K3/label.