Simplified association syntax

[Clashsoft]

Introduce a simplified and more grammatically correct way of defining associations.

Originally suggested by @azuendorf and @ulno.

Example

Every person has a home and every building has many inhabitants.
Every university has many students and every student has a university.
Every company has many employees and every person has an employer.

Open Questions

• How to express optional associations? E.g. not every person having a home or employer.