A-rule

A-rule (affixation rule) is the formalism used for generating affixes (prefixes, suffixes, infixes) in the UNLarium framework.

When to use a-rules

A-rules are used for prefixation, suffixation and infixation, i.e., for adding morphemes to a given base form. They are used for generating inflections (such as "book">"books", "love">"loved") or derivations (such as "dress">"undress", "write">"writer").

When not to use a-rules

A-rules are not to be used for composition (i.e., to form new words by combining or putting together old words, as in "give">"give in", "go">"have gone" or "man">"fireman").

Types of a-rules

There are two types of a-rules:

• simple a-rules involve a single action (such as prefixation, suffixation or infixation); and
• complex a-rules involve more than one action (such as circumfixation).

Simple a-rules

There are three types of simple a-rules:

• prefixation, for adding morphemes at the beginning of a base form
• suffixation, for adding morphemes at the end of a base form
• infixation, for changing the internal structure of a base form

Syntax

The syntax for simple a-rules is the following:

prefixation

CONDITION := “ADDED” < “DELETED”;

suffixation

CONDITION := “DELETED” > “ADDED”;

infixation

 CONDITION := “DELETED” : “ADDED”;

Where:

• CONDITION = tag (such as “PLR”, “FEM”, etc) or list of tags (“FEM&PLR”) that indicates when the rule should be applied
• ADDED = the string to be added (between quotes);
• DELETED = the string to be deleted (between quotes);

Examples

Prefixation

RULE	BEHAVIOR	BEFORE	AFTER
X:=”y”<”z”;	if X replace the string “z” by the string “y” in the beginning of the string	zabc	yabc
X:=”y”<1;	if X replace the first character of the string by “y”	zabc	yabc
X:=”y”<0;	if X add the string “y” to the beginning of the string	zabc	yzabc
X:=”y”<;	if X add the string “y” to the beginning of the string (idem previous)	zabc	yzabc
X:=”y”<<0;	if X add the string “y” and a blank space to the beginning of the string	zabc	y zabc
X:=”y”<<;	if X add the string “y” and a blank space to the beginning of the string (idem previous)	zabc	y zabc

Suffixation

RULE	BEHAVIOR	BEFORE	AFTER
X:=”z”>”y”;	if X replace the string “z” by the string “y” in the end of the string	abcz	abcy
X:=1>”y”;	if X replace the last character of the string by “y”	abcz	abcy
X:=0>”y”;	if X add the string “y” to the end of the string	abcz	abczy
X:=>”y”;	if X add the string “y” to the end of the string (idem previous)	abcz	abczy
X:=0>>”y”;	if X add a blank space and the string “y” to the end of the string	abcz	abcz y
X:=>>”y”;	if X add a blank space and the string “y” to the end of the string (idem previous)	abcz	abcz y

Infixation

RULE	BEHAVIOR	BEFORE	AFTER
X:=”y”;	if X replace the whole by “y”	X	y
X:=”z”:”y”;	if X replace the string “z” by “y”	azbc	aybc
X:=[2;3]:”y”;	if X replace the second to the third character by “z”	abcz	ayz
X:=Y;	replace the feature X by the feature Y	X	Y

Observations

Rules will only be applied if all conditions are true

X:=”y”<”z”; ( “zabc” changes to “yabc”, but “abc” remains “abc” since there is no "z" to be replaced)

Each action is applied only once (i.e, rules are not exhaustive)

PLR:=0>”s”; ("X" becomes "Xs", and not "Xssssss...")

The replacement rule applies only once to the same string

X:=”a”:”b”; ( “aaa” becomes “baa” and not “bbb”)

In prefixation and suffixation rules, the part to be deleted may be represented by the number of characters (without quotes)

PLR := “X”<””;	=	PLR := “X”<0;	(ABC becomes XABC)
PLR:= “X”<”A”;	=	PLR:= “X”<1;	(ABC becomes XBC)
PLR:= “XY”<”AB”;	=	PLR:= “XY”<2;	(ABC becomes XYC)
PLR:=””>”X”;	=	PLR:= 0>”X”;	(ABC becomes ABCX)
PLR:=”C”>”X”;	=	PLR:= 1>”X”;	(ABC becomes ABX)
PLR:=”BC”>”XY”;	=	PLR:= 2>”XY”;	(ABC becomes AXY)

In replacement rules, the part to be deleted may be omitted if the whole string is to be replaced

PLR:=”ABC”:”XYZ”;

=

PLR:=”XYZ”

(ABC becomes XYZ)

In replacement rules, the part to be deleted may be represented by an interval of characters in the format [beginning-end]

PLR:=”B”:”X”;

=

PLR:=[2-2]:”X”;

(ABC becomes AXC)

The symbol “^” is used for negation (“^MCL” means “not MCL”)

NOU&^MCL:=”x”:”y”; (If NOU and not MCL then replace “x” by “y”)

“<<” and “>>” add blank spaces

X:=”a”<<”b” (“bc” becomes “a bc” and not “abc”)

Common mistakes

• nou:= ”y”<”z”; (WRONG: Tags are case sensitive)
• NNN:= ”y”<”z”; (WRONG: NNN is not defined in the tagset)
• NOUFEM:=”y”<”z”; (WRONG: Tags must be separated by “&”)
• NOU,FEM:=”y”<”z”; (WRONG: Tags must be separated by “&”)
• NOU & FEM:=”y”<”z”; (WRONG: There can be no blank spaces between tags)
• X:=1<1; (WRONG: The left side must always be a string in a prefixation rule)
• X:=1>1; (WRONG: The right side must always be a string in a suffixation rule)
• X:=1; (WRONG: Replacement rules do not allow for numbers)
• X:=1:1; (WRONG: Replacement rules do not allow for numbers)

Complex a-rules

Complex a-rules are formed from the combination of simple a-rules:

• circumfixation (prefixation + suffixation), to add a prefix and a suffix at the same time
• prefixation + infixation, to add a prefix and a suffix at the same time
• infixation + suffixation, to add an infix and a suffix at the same time
• prefixation + infixation + suffixation, to add a prefix, an infix and a suffix at the same time

Syntax

Complex a-rules are formed by concatenating simple a-rules with ",":

circumfixation

CONDITION := “ADDED” < “DELETED” , "DELETED" > "ADDED";

prefixation + infixation

CONDITION := “ADDED” < “DELETED” , "DELETED" : "ADDED";

infixation + suffixation

CONDITION := "DELETED" : "ADDED" , "DELETED" > "ADDED";

prefixation + infixation + suffixation

CONDITION := “ADDED” < “DELETED” , "DELETED" : "ADDED" , "DELETED" > "ADDED";

Examples

Complex m-rules

RULE	BEHAVIOR	BEFORE	AFTER
X:=”x”<0, 0>"y";	if X add "x" to the beginning and "z" to the end of the string	A	xAy
X:=”x”<0, "A":"y";	if X add "x" to the beginning and replace "A" by "y"	ABC	xyBC
X:="A":"y", 0>"x";	if X replace "A" by "y" and add "x" to the end of the string	ABC	yBCx
X:=”x”<0, "A":"y", 0>"z";	if X add "x" to the beginning, replace "A" by "y" and add "z" to the end of the string	ABC	xyBCz

Observations

Complex a-rules are also used to integrate different simple a-rules

ORD:="1">"1st"; ORD:="2">"2nd"; ORD:="3">"3rd";

ORD:="1">"1st", "2">"2nd", "3">"3rd";

Actions are applied from left to right (i.e., order is important)

PLR := "s" > "ses", "y" > "ies"; (kiss > kisses, city > cities)

PLR := "y" > "ies", "s" > "ses"; (kiss > kisses, city>cities>citieses)

Formal syntax for a-rules

A-rules comply with the following syntax:

<A-RULE>           ::= <CONDITION> “:=” <ACTION> [, <ACTION>]* “;”
<CONDITION>        ::= <ATAG>[“&”[“^”]<ATAG>]*
<ATAG>             ::= {one of the tags defined in the UNDLF Tagset}
<ACTION>           ::= <LEFT APPENDING> | <RIGHT APPENDING> | <REPLACEMENT>
<LEFT APPENDING>   ::= <ADDED>	 {“<” | “<<”} 	[ <DELETED> ]
<RIGHT APPENDING>  ::= [ <DELETED> ]	 {“>” | “>>”} 	<ADDED>
<REPLACEMENT>      ::= [ <STRING> ":" ] <ADDED> | "[" <INTEGER> "-" <INTEGER> "]" ":"  <ADDED>
<ADDED>            ::= <STRING> 
<DELETED>          ::= <STRING> | <INTEGER>  
<STRING>           ::= “ “ “ [a..Z]+ “ “ “
<INTEGER>          ::= [0..9]+

where

<a> = a is a non-terminal symbol
“a“ = a is a constant
[a] = a can be omitted
a | b = a or b
{ a | b } = either a or b
a* = a can be repeated 0 or more times
a+ = a can be repeated 1 or more times