Improvements to Synchronic Flow Processing §11.3.1.4.

[skynavga]

• section 3.2.3 (substantive)

• add step invoking 11.3.1.3 Intermediate Document Construction
  and 11.3.1.4 Synchronic Flow Processing;

N.B. The following two changes are strictly editorial, the purpose of which is to combine the paragraph that immediately precedes step (1) and the paragraph that immediately follows step (11), and to place the combined results to immediately before the [flow transformation] label.

• section 11.3.1.4 (editorial)

• move paragraph "Each intermediate ... as follows:" at beginning
  of label [flow transformation] to immediately before the label
  [flow transformation], rewriting it as follows:

"For the purpose of performing presentation processing, for each
intermediate synchronic document $DOC_{inter_i}$ produced by
11.3.1.3 Intermediate Synchronic Document Construction, invoke the
following [flow transformation] procedure in order to map each
$DOC_{inter_i}$ to a corresponding XSL FO document instance $F_i$."

• section 11.3.1.4 (editorial)

• incorporate paragraph "For each resulting document instance F, ..."
  at end of [flow transformation] into the text of the above rewritten
  paragraph;

• section 11.3.1.4 (substantive)

• in step (6), handle "image in a block context";

• section 11.3.1.4 (substantive)

• in step (8), subdivide into (a) and (b), copying
  current text into (a) and adding new text defining the mapping of
  inline images in (b);

[nigelmegitt]

in order to map each $DOC_{inter_i}$ to a corresponding XSL FO document instance $F_i$.

This is a change of meaning, which I don't support, since it goes from "apply formatting and rendering semantics consistent with that prescribed by [XSL-FO 1.1]" to "map ... to a corresponding XSL FO document instance". We've always said before that while XSL-FO provides the semantics of presentation, use of XSL-FO is not in fact a requirement.

By the way, that text is no longer correct either because we are now prepared to use some presentation semantics that are absent from XSL-FO, but that may be present in CSS or SVG, for example.

If the semantics being hinted at for TTML2 2nd Edition are needed we should check if we have the opportunity to build them normatively into a TTML2 CR3 sooner.

[skynavga]

@nigelmegitt it is not a change of meaning or words, the language is already present as the first paragraph under [flow transformation] 11.3.1.4

Each intermediate synchronic document produced by 11.3.1.3 Intermediate Synchronic Document Construction is mapped to an XSL FO document instance, F, as follows:

@nigelmegitt we already deal with your "we are now prepared to use some presentation semantics that are absent from XSL-FO" comment in the last note in the prologue of 11.3.1.4 as well as step (1) under [flow transformation]

@nigelmegitt regarding your last comment, I will upgrade this to substantive and attempt to deal with things here for CR3