Eberon non VAR arguments are read only

Original Oberon-O7 allows to change procedure arguments (to use them as ordinary variables) unless they are non-VAR ARRAY or RECORD. Eberon makes this rule more consistent - all non-VAR arguments are read-only. This restriction is introduced in the first place to support implicit type narrowing for POINTER arguments. But anyway reusing arguments as variables I personally consider as a bad practice because their scope is a whole procedure and possibility of modifing requires more attention while reading.