ACE 6.7 Construction Rules

The construction rules define admissible sentence structures for ACE 6.7. Note that every ACE sentence is a syntactically acceptable English sentence, but not every English sentence is an ACE sentence.

Note: A sentence prefixed with * is not part of ACE, but serves as counter example.

Words

ACE function words and some fixed phrases are predefined and cannot be changed by users. Function words are determiners, quantifiers, coordinators, negation words, pronouns, query words, modal auxiliaries, copula be, and Saxon genitive marker 's. Fixed phrases are, for instance: there is ... and it is not possible that ... .

ACE content words are nouns, verbs, adjectives, adverbs and prepositions. Content words can be simple (code), or compound with hyphens (check-code).

Phrases

Noun Phrases

Singular Countable Common Noun Phrases

a card
the card
1 card
one card
no card
every card
each card
not every card
not each card

all cards
no cards

The following determiners can be used interchangeably: a and 1 and one, every and each, not every and not each.

The noun phrase all cards is syntactic sugar for every card, and the noun phrase no cards is syntactic sugar for no card.

Plural Countable Common Noun Phrases

Plural countable common noun phrases can be collective:

the cards
some cards
3 cards
three cards

or distributive:

each of the cards
each of some cards
each of 3 cards
each of three cards

Integers up to 12 used as determiner as in 12 cats can be written in characters, i.e. twelve cats. Larger integers must be written in digits.

Mass Common Noun Phrases

some water
no water
all water
not all water

Proper Names

Proper names can be singular and plural, and can occur without or with the definite determiner. Multiwords like United-Nations must be hyphenated.

John
Mr-Miller
the United-Nations

Integer and Real Numbers

Integer and real numbers are predefined.

An integer is a non-empty sequence of digits (0-9). A real number consists of a non-empty sequence of digits (0-9) followed by a period followed by a non-empty sequence of digits (0-9). Positive integers and positive real numbers must not be prefixed by a plus sign (+). Negative integers and negative real numbers are prefixed by a minus sign (-).

0
12
-2
0.0
0.2
2.0
3.141
-2.718

Arithmetic Expressions

Arithmetic expressions are built from numbers, variables and proper names with the help of the operators +, -, *, /, ^. Standard operator precedence applies. Sub-expressions can be put in parentheses to modify the precedence of the operators. This applies specifically to iterated occurrences of the exponentiation operator ^. The ACE parser APE does not evaluate expressions.

1 + 2 / X * 4
(1 + 2) / X * 4
Pi/2
2 ^ 3
2 ^ (3 ^ 4) vs. (2 ^ 3) ^ 4

Strings

Strings consists of a sequence of Unicode characters enclosed in double quotes "...". Quotation marks and backslashes within strings have to be escaped by a backslash.

Strings, variables, proper names and bracketed strings can be concatenated by the left-associative operator &. The ACE parser APE does not perform concatenations.

""
"abc"
"ab\"cd"
"ab\\cd"
"abc" & "123"

Sets and Lists

Sets consist of a sequence of elements in braces {...}. Lists consist of a sequence of elements in brackets [...]. Elements of sets and lists are numbers, arithmetic expressions, variables, strings, proper names, and sets and lists.

{}
{3, 6, [1,2]}

[]
[3, 4, 5, "ab", John, 1+2]

Operations on sets and lists could be expressed in natural language. Here are possible examples.

{} is a subset of {3, 6}
X is an element of [3, 4, 5]

Non-Reflexive Pronouns

Non-reflexive pronouns third person singular and plural are available for all sentences.

he
she
he/she
it
they
him
her
him/her
them

Non-reflexive pronouns second person singular and plural are available for commands.

you

Reflexive Pronouns

Reflexive pronouns third person singular and plural are available for all sentences.

itself
himself
herself
himself/herself
themselves

Reflexive pronouns second person singular and plural are available for commands.

yourself
yourselves

Indefinite Pronouns

someone
somebody
something
no one
nobody
nothing
everyone
everybody
everything
not everyone
not everybody
not everything

The following indefinite pronouns can be used interchangeably: someone and somebody, no one and nobody, everyone and everybody, not everyone and not everybody.

Generalised Quantifiers

Generalised quantifiers are followed by positive integers.

Noun phrases with generalised quantifiers can be collective:

at least 2 cards
at most 2 cards
more than 10 cards
less than 3 cards
exactly 3 cards

or distributive:

each of at least 2 cards
each of at most 2 cards
each of more than 10 cards
each of less than 3 cards
each of exactly 3 cards

Nobody and Nothing But

The special determiners nobody but, nothing but, and their variant no ... but are used with bare plural noun phrases, bare mass noun phrases or proper names.

nothing but apples
nothing but water
nobody but John
no man but John

Measurement Nouns

Measurement noun phrases are built from numbers followed by measurement nouns and optionally followed by of and a bare mass noun or a bare plural noun.

Note that symbols of SI base units as measurement nouns are predefined in the lexicon of the Attempto Parsing Engine (APE).

2 m
31.2°C
1.4 l of water
3 kg of apples

Measurement noun phrases can be used in the singular and in the plural.

3 kg of apples is heavy.
3 kg of apples are heavy.

Variables

Variables can be introduced as noun phrase apposition, and can then be used as noun phrases. Variable names consist of a single upper case letter, optionally followed by an integer.

A man X sleeps. X is young.
If somebody D1 is a dog then D1 is an animal.

If a variable is introduced as apposition to something then it is possible to omit something. These variables are called "bare".

X weighs 300 kg. X is heavy. (= Something X weighs 300 kg. X is heavy.)

Noun Phrase Conjunction

The conjunction of noun phrases creates a plural entity that can be anaphorically referred to.

A man and at least 2 women wait. They are tired.

Modifying Nouns and Noun Phrases

Adjectives

A common noun can optionally be preceded by a positive, comparative, or superlative adjective. Adjectives can be conjoined by and.

a rich customer
a rich and satisfied customer
a richer customer (= a more rich customer)
a richer and more satisfied customer
a richest customer (= a most rich customer)
a richest and lucky customer

Relative Clauses

A relative clause can optionally follow a noun phrase, a proper name, or an indefinite pronoun. Relative clauses can be coordinated by and and by or.

a customer that is rich
a customer who is rich and who is well-known
a man who waits or who sleeps
John who waits
some men each of who waits
everything which is important

Variables in Apposition

Variables can optionally occur in apposition to a noun phrase. Variable names consist of a single upper case letter, optionally followed by an integer.

a customer X
the customer C1

Genitives

Various genitive constructs can optionally be attached to a noun phrase: of-prepositional phrases, Saxon genitives and possessive pronouns. Possessive pronouns are non-reflexive (your, its, his, her, his/her, their), or reflexive (your own, its own, his own, her own, his/her own, their own). Note that the Saxon genitive can only be used with a single noun while the of-prepositional phrase can be followed by a conjunctive noun phrase.

a customer of John
a dog of John and Mary (= a dog of {John and Mary})
John's customer
John and Mary's dog (= John and {Mary's dog})
everybody's customer
every man's dog
X's dog
his customer
his own customer
your customer

Verb Phrases

ACE verbs occurring in declarative or interrogative sentences are third person and simple present tense. Passives are built with the past participle and must have a prepositional phrase ... by ... . ACE verbs occurring in imperative sentences are second person.

Verbs can be intransitive (wait), transitive (enter something), and ditransitive (give something to somebody / give someone something).

Phrasal particles and those prepositions that introduce a complement of a transitive verb, must be hyphenated to the verb. Prepositions for the indirect object of ditransitive verbs are not hyphenated since they do not immediately follow the verb.

The copula be as a special case is treated separately (see further down).

Intransitive, Transitive and Ditransitive Verbs

Here are some examples. For sentences with transitive and ditransitive verbs, the active and the semantically equivalent passive are given.

John waits.
John enters a card. (= A card is entered by John.)
John fills-in a form. (= A form is filled-in by John.)
John gives a card to a customer. (= A card is given to a customer by John.)
John gives a customer a card. (= A customer is given a card by John.)

Copula

The copula be must be followed by a noun phrase, an adjective phrase, a concatenation of prepositional phrases or a query word. For the use of the copula in interrogative sentences see Interrogative Sentences.

Some examples of the use of the copula.

John is a rich customer.
John's age is 32.
John and Mary are two teachers.
John is rich.
John is in the garden on the hill.
John is who?

An adjective phrase following the copula can use a transitive or an intransitive adjective. In both cases, the adjective can be positive, comparative, or superlative. Transitive adjectives always take a prepositional phrase as a complement and the preposition must be hyphenated to the adjective. Intransitive adjectives following a copula can be conjoined, but transitive adjectives cannot.

John is rich.
John is richer. (= John is more rich.)
John is richest. (= John is most rich.)
A customer is rich and more important and most successful.
John is fond-of Mary.
John is more fond-of Mary. (= John is fonder-of Mary.)
John is most fond-of Mary. (= John is fondest-of Mary.)
*A customer is rich and interested-in a bank.

For the positive and comparative forms, a comparison target can be defined using as ... as or more ... than, respectively. In this case conjunction of the adjectives is not possible.

John is as rich as Mary.
John is richer than Mary.
John is as fond-of Mary as Bill.
John is more fond-of Mary than Bill.
*A customer is as rich as John and important.
*A customer is richer than John and important.

In the case of transitive adjectives, one can repeat the preposition in order to make the object be the target of the comparison. (In the examples above, the subject was the target of the comparison.)

John is as fond-of Mary as of Sue.
John is more fond-of Mary than of Sue.

Negating Verb Phrases

Verb phrases are negated by does/do not and is/are not. For sentence negation see Subordination.

John does not enter a code. 
The men do not wait.
Some water is not drinkable.
The men are not tired.

Negation as Failure of Verb Phrases

In addition to logical negation, ACE provides negation as failure (... does/do/is/are not provably ...). For negation as failure of sentences see Subordination.

John does not provably wait.
The men do not provably work.
John is not provably a teacher.
The men are not provably admitted.

Modal Verb Phrases

ACE provides modality with modal auxiliaries for possibility (can/cannot/can not/can't), necessity (must/have to/does not have to), recommendation (should/should not/shouldn't), and admissibility (may/may not). For modal sentences see also Subordination.

John can wait.
John cannot wait. (= John can not wait., = John can't wait.)
John must wait. (= John has to wait.)
John does not have to wait.
John should wait.
John should not wait. (= John shouldn't wait.)
John may wait.
John may not wait.

Coordinating Verb Phrases

Verb phrases can be coordinated by and and by or.

John waits and eats a burger.
John is rich or earns his own income.

Modifying Verb Phrases

All verb phrases can be modified by adverbs and by prepositional phrases. Modifiers can precede the verb phrase or — with the exception of sentence subordination (see further down) — follow it.

As the following examples show, not each choice of positioning an adverb or a prepositional phrase is felicitous, but being able to put adverbs and prepositional phrases in different positions allows you to respect English pragmatics.

Adverbs and prepositional phrases can precede the verb phrase.

A customer manually inserts a card.
A customer into a slot inserts a card.
Every customer usually is curious.
Every customer in the beginning is inexperienced.

Adverbs and prepositional phrases can follow the verb phrase.

A customer inserts a card manually.
A customer inserts a card into a slot.
Every customer is curious usually.
Every customer is inexperienced  in the beginning.

Both positions can be combined.

A customer manually inserts a card into a slot.

In sentence subordination (Subordination) modifiers of the verb of the main phrase must occur immediately before the verb. No modifiers are allowed between the verb of the main phrase and that, respectively to.

John seriously in the morning believes that Mary fills-in a form.
John seriously in the morning wants to fill-in a form.

Adverbs can be used in their positive, comparative, or superlative forms.

A customer waits patiently.
A customer waits more patiently.
A customer most patiently waits.

Observe the difference between:

A student is interested-in a course.
A student is interested in a classroom.

If several modifiers are used, two or more adverbs must be conjoined by and, two or more prepositional phrases must be concatenated, and a sequence of adverbs and prepositional phrases must be concatenated.

A customer inserts a card carefully and manually.
A customer waits in a bank in the morning.
A customer carefully and manually inserts a card into the slot in the bank.
John usually in the current year is a rich customer in England. 

Declarative Sentences

Declarative sentences are simple sentences, there is/are-sentences, boolean formulas, and composite sentences.

Simple Sentences

Simple sentences have the structure

noun phrase + verb phrase

A customer waits.
A customer inserts a card.
A customer gives a card to a clerk.
A customer gives a clerk a card.
A customer inserts a card manually into a slot.
A customer manually inserts a card into a slot.

there is/are-Sentences

It is possible to create well-formed sentences without a verb, by using the there is/are construction.

there is + noun phrase

there are + noun phrase

This construct just introduces the entities described by the noun phrase into the discourse, or — if negated — denies their existence. For this reason noun phrases following there is/are cannot be and cannot contain definite noun phrases, universally quantified noun phrases, proper names, numbers, arithmetic expressions, strings, sets, or lists.

There is a customer.
There is some water.
There are more than 6 clerks.
There are a cat and 2 dogs.
There is X.
There is no man who sleeps.
*There is a cat in a garden.
There is a cat that sleeps.

Boolean Formulas

Boolean formulas also count as sentences. They are built from numbers, arithmetic expressions, proper names and variables with the help of the comparison operators =, \=, >, >=, < and =<. As other sentences boolean formulas can be coordinated by and, or, ,and and ,or. The ACE parser APE does not evaluate boolean formulas.

10 = 4 + 6.
X \= 2.
5 > 3.
X >= 13.4 and X < 20.
2 ^ (2 ^ 2) = (2 ^ 2) ^ 2.

Composite Sentences

Composite sentences are recursively built from simple sentences, there is/are-sentences, boolean formulas, and other composite sentences with the help of the predefined constructors:

Coordinated Sentences

Sentences can be coordinated by and, or, ,and and ,or.

Coordination by and and or is governed by the standard binding order of logic, i.e. and binds stronger than or. The coordinators ,and and ,or can be used to override the standard binding order.

The screen blinks and John waits.
The screen blinks or John waits.
The screen blinks or John waits, and Mary enters a card.

Locally Quantified Sentences

There are existential and universal local quantification. For the treatment of the semantics of quantifiers in ACE, see the ACE interpretation rules.

Local existential quantification is expressed by indefinite determiners like a, or explicitly by there is/are.

There is a card.
There is some water. 
There are at least 2 cards.
John enters a card. 
John drinks some water.

Local universal quantification is expressed by the determiner every, and its variants. Note that universal quantification can also be expressed by an if ... then construct.

Every man waits. (= If there is a man X then the man X waits.)
John enters every card. (= If there is a card X then John enters the card X.)

Globally Quantified Sentences

There are existential and universal global quantification in which the quantifiers are moved to sentence initial position.

Global existential quantification is expressed by:

there is ... that ...
there are ... that ...

Global universal quantification is expressed by:

for every
for each
for each of
for all 

Here are some examples.

There is a code that every clerk enters.

For every code a clerk enters it.
For each of 3 men there is a bed.
For all water there is a container.

Subordination

ACE knows five forms of sentence subordination:

Conditional Sentences

Conditional sentences are built with the help of the if-then construct that subordinates two simple or composite sentences.

If John enters a card then the automated-teller accepts it.
If John enters a card and he waits then the automated-teller accepts the card or rejects it.
Logical Negation

Complete sentences can be negated. For the negation of nouns phrases see Noun Phrases, and for the negation of verb phrases see Verb Phrases

Negation of sentences is expressed by the fixed phrases it is false that ... , or by it is not true that ... . For coordinated sentences the word that has to repeated. Note that for backwards compatibility ACE offers also the phrase it is true that ... .

It is false that a screen blinks. 
It is false that a screen blinks and that John enters a code. 
Negation as Failure

Negation as failure can be applied to complete sentences. For negation as failure of verb phrases see Verb Phrases.

Negation as failure of sentences is expressed by the fixed phrase it is not provable that ... . For coordinated sentences the word that has to repeated.

It is not provable that a screen blinks.
It is not provable that a screen blinks and that John enters a code.
Modality

Modality can be used with complete sentences. For the modality of verb phrases see Verb Phrases

Modality of sentences is expressed by the fixed phrases it is possible that ... , it is not possible that ... , it is necessary that ... , it is not necessary that ... , it is recommended that ... , it is not recommended that ... , it is admissible that ... , it is not admissible that ... . For coordinated sentences the word that has to repeated.

It is possible that John waits.
It is not necessary that John enters a card and that he types a code.
It is recommended that the surgeon operates the patient.
It is not admissible that the patient takes his/her own medicine.
Sentence Subordination

In sentence subordination a transitive verb takes a complete sentence as an object.

A clerk believes that a customer inserts a card.

If and only if the main sentence and the subordinated sentence have the same subject as in

John wants that John inserts a card.

then sentence subordination can be more concisely expressed as

John wants to insert a card.

Notice that adverbs and prepositional phrases modifying the verb of the main sentence can only occur before the verb of the main sentence as in the example below, but are not allowed between the verb of the main sentence and that, respectively to.

John eagerly in the morning wants to insert a card.

Interrogative Sentences

ACE allows three forms of interrogative sentences: yes/no queries, wh-queries and how much/many-queries. Interrogative sentences must end with a question mark.

Yes/No queries can be answered by yes/no.

Does John enter a card?
Does John not wait?
Do John and Mary wait in a garden?
Is the card valid?
Is the card not valid?
Is it true that a man waits?
Is it false that a man waits?

The wh-queries who, whose, what, and which ask for the subject or an object of a sentence, while how, where, and when ask for modifiers of the verb.

Since the query words can often be placed before the verb and after the verb most questions have alternative equivalent formulations.

Who waits?
Who wait? (= Who waits?)
Each of who waits?
Whose dog barks?
A card of who is valid?
Who does John not see? (alternatively: John does not see who?)
Who is John? (alternatively: John is who?)
What does a man not eat? (alternatively: A man does not eat what?)
Which customer enters a card and types a code?
How does John enter a card? (alternatively: John enters a card how?)
Where does John wait? (alternatively: John waits where?)
When does John wait? (alternatively: John waits when?)
There is who? (alternatively: Who is there?)
There is which man? (alternatively: Which man is there?)
Where is John? (alternatively: John is who?)

The how much/many-queries ask for the amount of a mass or measurement noun, or for the number of countable nouns. The queries can be used as subjects or objects of a sentence.

How much water boils?
How many men wait?
How many men have how many apples?
John gives how much food to how many children?

Imperative Sentences

ACE supports simple imperative sentences, briefly called commands. A command consists of a noun phrase (the addressee), followed by a comma, followed by a — possibly negated — uncoordinated verb phrase. A command must end with an exclamation mark.

John, go to your own bank!
John and Mary, clean yourselves!
Every dog, do not bark!
John's brother, return the book to Mary!

ACE Texts

An ACE text is a sequence of declarative, interrogative and imperative sentences. All sentences can anaphorically refer to preceding declarative sentences, but not to interrogative and imperative sentences.

Mary enters a card into a machine. Its screen blinks or Mary waits.

A man has a car. Does he see the car? John, identify the car!
2013-07-31