Semantic entities versus syntactic entities

["Costello, Roger L." <costello@mitre.org>]

Hi Folks,

Compare these two sentences:

    1. Say your name out loud.

    2. Say "your name" out loud.

In the first sentence we expect to hear that person's name. In the second sentence we expect to hear the words, "your name."

In the first sentence the words "your name" are semantic entities. In the second sentence the words "your name" are syntactic entities.

By quoting the words we have turned off the normal semantic interpretation of the words.

In XML there is an analogous situation:

    1. <altitude>

    2. &lt;altitude>

In the first case we expect an XML parser to process it as an element. In the second case we expect an XML parser to process it as literal text.

In the first case <altitude> is a semantic entity to an XML parser. In the second case &lt;altitude> is a syntactic entity to an XML parser.

By escaping the less-than symbol we have turned off its normal semantic interpretation.

Comments?

/Roger