[Oberon] Clarifying type compatibility in Oberon-07

[August Karlstrom]

On 2017-10-05 17:56, Jörg wrote:
> Okay. NW’s compiler allows it.
> If you write p2(4,5) it’s debatable whether p2 is a “name of a procedure“...

Assignment rule 7 wouldn't be so verbose if it wasn't to specify that 
the expression must be a procedure constant. So Oberon-2 as do 
"standard" Oberon-07 uses structural equivalence only for procedure 
variable initialization with a procedure (constant).

-- August