[Oberon] Case statements containing base type labels

[August Karlstrom]

On 2023-08-28 13:15, joerg.straube at iaeth.ch wrote:
> case labels *must be extensions of T*

As mentioned by Diego, type extension is defined so that each record 
type is a (trivial) extension of itself:

"A type T extends a type T0, if it equals T0, or if it directly extends 
an extension of T0."

https://miasap.se/obnc/oberon-report.html#sec6.3

However, the same dilemma occurs also if we consider strict extensions, 
for example

	CASE animal OF
		Squirrel: ... |
		Whale: ... |
		Mammal: ...
	END


/August