4.2 AND / OR

4.2.1 AND   (Conjunction)
Definition:  And defines a conjunctive relation between concepts

Relation "and" is used for grouping UWs together to say the same thing about them. Each relation "and" connects two UWs and the direction of it is from the posterior UW toward the prior UW. For example, the UNL of "A, B and C" will be "and (B, A); and (C, B);”. "C" will be the main UW in this group.

A related issue, is how to express "etc." or "et cetera", for example the underlined part in "Please inform us of your travel plans, i.e. arrival time, carrier, etc.". "etc." or "et cetera" means "and the rest", an UW that expresses the meaning of "the rest" will be used. Also "and so on/forth" will be expressed in the same way.

 The following is the UNL expression of this sentence above.

Example 1

Attribute @request is not defined in the specifications 2.0 (November 1999). It is necessary to express "please do something", and will be added to the specifications.

"but" : A coordinate conjunction for contrastive words, phrases and clauses.

Example2

Comments on Example2

This sentence can also be said in the way of "It's a pencil and not a pen". The difference between the two sentences is that in the original sentence "a pencil" is the main (focused) UW but in the second one "not a pen" is. In an UNL expression, the main (focused) UW will be the entry of a sentence. Using this characteristic of UNL expressions, it is possible to express these two sentences in different ways of UNL expressions, and vice versa, different sentences are also possible to be generated from the different UNL expressions.

Example3

4.2.2 OR   (Disjunction)
Definition: Or defines disjunctive relation between two concepts

Relation "or" is used for grouping UWs in order to say that something is true or not for one of them. The same as "and", each relation "or" connects two UWs and the direction of it is from the posterior UW toward the prior UW. For example, the UNL of "A, B or C" will be "or (B, A); or (C, B);"."C" will be the main UW in this group.

Direction of Relation "and" and "or"

We defined the last UW (the UW of the most right member) of a group of coordinating words and phrases as the main UW for the following reasons. In many languages, for example English, a verb often conjugates according to the last word when taking such a group of words and phrase as its subject. To put the last word in the central (as the main UW) by either way of linking it to the verb directly or making a scope in which it is the entry, will make it easier to refer the necessary information about subject for the verb.

From the viewpoint of an UNL expression, the information of the entry and the order of members in such a group is the essence.

Last updated : 2000/09/21