Modula-3: Block statements

## Blocks

A block statement has the form:

        Decls BEGIN S END

where `Decls` is a sequence of declarations and `S` is a statement. The block introduces the constants, types, variables, and procedures declared in `Decls` and then executes `S`. The scope of the declared names is the block.

    Last modified on Wed Apr  3 09:39:12 PST 1996 by heydon
         modified on Mon Apr 18 14:00:59 PDT 1994 by kalsow