[sv-bc] Type/size propagation does not stop at parens (6.6.2, V-2005)

According to 6.6.2, regarding propagating the type and size of an
expression "back down to the context-determined operands of the
expression" --

    "When propagation reaches a simple operand as defined in 5.2 (a
primary as defined in A.8.4), then that operand shall be converted to
the propagated type and size. If the operand must be extended, then it
shall be sign-extended only if the propagated type is signed."

Yet every parenthesized expression is a primary

      primary --> ( mintypmax_expression )
              --> ( expression )

and width propagation does not stop at parens.  For example, the
following yields |0001000|1001000|, not |0000000|1000000|.

   module m;
   reg [6:0] a;
   initial begin
     a = (3'b111 + 3'b001);
     $display("|%b|%b|", a, 7'b1000000 + (3'b111 + 3'b001));
   end
   endmodule

Note also that "simple operand" is not actually defined in 5.2.

Are parenthetical comments even normative?

-- Brad