Practical Grammar 8

The Difference between Defining Equations and Constraining Equations

There are several types of equations that can be used in annotations. So far, we have encountered the following two:

(1) ↑=↓1;
(2) (↑ OBJ) =↓2;

These equations are both defining equations.

Defining equations add their information to an f-structure.

There is a second kind of equation, which we have not seen yet, but which you will need for the following exercise. These are called constraininig equations.

Constraininig equations test whether their information is contained in an f-structure. They do NOT add the information themselves.

Illustration:

Case 1:

Imagine you have the following defining equation:

(↑ TENSE) = pres;

• it turns the f-structure [] into the f-structure [TENSE pres], i.e. it adds its information to the f-structure.
• it turns the f-structure [TENSE pres] into the f-structure [TENSE pres], i.e. it adds its information to the f-structure. If the information was already there, the f-structure remains the same.

Case 2:

Now, imagine you have the following constraining equation:

(↑ TENSE) =_c pres

• it marks the f-structure [] as ill-formed, since it does not contain the information TENSE pres, i.e. the constraining equation is a test on an f-structure.
• it marks the f-structure [TENSE pres] as well-formed, but does not change it.

When to use a constraining equation:

Constraining equations are used when one item depends on some other item's adding a particular piece of information to an f-structure.

The Syntax of Constraining equations in xlfg

Since xlfg does not use subscripts, it uses "==" as constraining equations.

Illustration:

(↑ TENSE) =c pres becomes (↑ TENSE) == pres; in xlfg.

Complement Clauses

Exercise 8.1 (based on section 5.1 of the textbook)

• Go to https://xlfg.labri.fr/.
• Open your latest grammar.
• Add the words in the following sentences:

(1) Oscar thinks Sarah likes musicals
(2) Oscar thinks that Sarah likes musicals

• Make any further changes that are necessary to obtain exactly the f-structure (10) on p. 101 for (1)-(2).
• Extend your grammar to predict the following facts:

(3) Oscar enquires whether Sarah likes musicals
(4) *Oscar enquires Sarah likes musicals
(5) *Oscar enquires that Sarah likes musicals

For sentence (3), you should obtain an f-structure which is identical to that of sentence (1), with the exception that the CLTYPE of (3) should be INTER.

Now make sure that your grammar does not license the following example:

(6) *Oscar thinks whether Sarah likes musicals

This requires the use of a constraining equation in one place!

Note: the solution to this exercise is going to be posted under the name Practical Grammar 6_solution.

Homework

For next week, read pages 102-113 in the textbook.

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