RE: [EXI] Circular production with no terminal symbol

Hi Yuri,

In 8.5.4.2.1, we will describe that you need to remove a production
'G_i, j -> RHS(G_i,k)_h'  when that would generate either a self-loop
or a production that has been previously replaced.

Thank you for pointing this out.

-taki 


-----Original Message-----
From: public-exi-comments-request@w3.org [mailto:public-exi-comments-request@w3.org] On Behalf Of Yuri Delendik
Sent: Wednesday, October 15, 2008 6:22 PM
To: Taki Kamiya; public-exi-comments@w3.org
Subject: Re: [EXI] Circular production with no terminal symbol


Hello Taki,

The question appeared when I was trying to generate the EXI grammar for TTFMS CBMS data by rules described in EXI specification. The
problem appears when PersonNameType type (from CBMS/schema/mpeg7.xsd) is processed. In case when prototype grammar looks like

G_0: G_i
G_i: G_j
G_j: G_i

non-terminal forms cannot be illuminated if the removing procedure starts from G_0. I had to tweak default/described algorithm to
make it finite. 

Regards,
Yuri Delendik



----- Original Message ----
From: Taki Kamiya <tkamiya@us.fujitsu.com>
To: yury_exi@yahoo.com; public-exi-comments@w3.org
Sent: Wednesday, October 15, 2008 5:18:24 PM
Subject: Re: [EXI] Circular production with no terminal symbol

Hi Yuri,

Given the following schema, which is a little more complex than the one
you  provided:

<xs:sequence minOccurs="0" maxOccurs="unbounded">
  <xs:element name="a" minOccurs="0" maxOccurs="unbounded"/>
  <xs:element name="b" minOccurs="0" maxOccurs="unbounded"/>
  <xs:element name="c" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>

The normalized grammar would look like this:

PTA :
  SE(A) PTA
  SE(B) PTB
  SE(C) PTC
  EE

PTB:
  SE(B) PTB
  SE(C) PTC
  SE(A) PTA
  EE

PTC:
  SE(C) PTC
  SE(A) PTA
  SE(B) PTB
  EE

When you normalize the grammar, please remove self-recursion
production with no terminal symbols of the form:
G: G

We failed to mention to remove such production during normalization,
and we appreciate that you caught this issue.

Thanks!

-taki

Received on Wednesday, 12 November 2008 20:54:23 UTC