These construction rules define admissible sentence structures for ACE 6.0. Every ACE sentence is an acceptable English sentence, but not every English sentence is an ACE sentence.
Note: A sentence prefixed with * is not accepted by the ACE parser.
ACE function words and some fixed phrases are predefined and cannot be changed by users. Function words are determiners, quantifiers, prepositions, coordinators, negation words, pronouns, query words, copula be, and Saxon genitive marker 's. Fixed phrases are: there is/are ... such that, and it is (true/false/(not) possible/(not) necessary/not provable) that ... .
ACE content words are nouns, verbs, adjectives and adverbs. Content words can be simple (code), or compound with hyphens (check-code).
Integer and real numbers are predefined.
a/the/1/one card, no card, every/each card, not every/each card
collective reading: the cards, some cards, 3/three cards, all cards, no cards distributive reading: each of the cards, each of some cards, each of 3/three cards
some water, no water, all water, not all water
John, Mr-Miller
12, -2, 3.141
Arithmetic expressions are built from numbers and variables with the help of the operators +, -, *, /. Standard operator precedence applies. Sub-expressions can be put in parentheses to modify the precedence of the operators. Expressions are not evaluated by the parser.
(1 + 2) / X * 4
Strings consists of any characters in double quotes "...". Strings can be concatenated by the operator &. This operation is not performed by the parser.
"", "abc", "this is a string!", "abc" & "123"
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 can be expressed in natural language and are not evaluated by the parser. Here are possible examples.
{} is a subset of {3, 6}
X is an element of [3, 4, 5]
Non-reflexive pronouns are available for the nominative and accusative cases.
it, he, she, he/she, they it, him, her, him/her, them
Reflexive pronouns are available for the accusative and dative cases.
itself, himself, herself, himself/herself, themselves
someone, somebody, something, no one, nobody, nothing, (not) everyone, (not) everybody, (not) everything
Generalised quantifiers are followed by positive integers.
collective reading: (not) at least 2 cards, (not) at most 2 cards, (not) more than 10 cards,
(not) less than 3 cards, (not) exactly 3 cards
distributive reading: each of at least 2 cards, each of at most 2 cards, each of more than 10 cards,
each of less than 3 cards, (not) each of exactly 3 cards
The special determiners nobody/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 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. Symbols of SI base units as measurement nouns are predefined in the lexicon.
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/are heavy.
Variables can be introduced in a noun phrase apposition (see below), and can then be used as noun phrases.
A man X sleeps. X is young. If somebody X is a dog then X is an animal.
The conjunction of noun phrases creates a plural object that can be anaphorically referred to.
A man and at least 2 women wait. They are tired. A rich customer and a clerk enter a bank.
A 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
A relative clause can optionally follow a noun, a proper name, a pronoun, or a variable. Relative clauses can be coordinated by and and by or.
a customer who is rich a customer who is rich and who is well-known a man who waits or who sleeps John who waits he who sleeps some men each of who waits everything which is important X which is expensive
Variables can optionally occur in apposition.
a customer X the customer C1
Various genitive constructs can optionally be attached to the noun: of-prepositional phrases, Saxon genitives and possessive pronouns. Possessive pronouns are non-reflexive (its, his, her, his/her, their), or reflexive (its own, his own, her own, his/her own, their own).
a customer of John a dog of John and Mary John's customer everybody's customer every man's dog X's dog his (own) customer
ACE verbs are third person singular/plural, indicative, simple present tense, active or passive. Passives must have a prepositional phrase ... by ... .
Verbs can be intransitive (wait), transitive (enter something), and ditransitive (give something to somebody / give someone something). Note that the two forms John gives a card to a customer. and John gives a customer a card. of a sentence with a ditransitive verb have the same meaning. But not all ditransitive verbs support both forms.
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 don't immediately follow the verb.
The copula be as a special case is treated separately (see further down).
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.)
The copula be can be followed by a noun phrase, an adjective phrase, or a concatenation of prepositional phrases.
Some examples of the copula followed by noun phrases.
John is a rich customer. John's age is 32. John and Mary are some teachers.
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.
An example of copula plus prepositional phrases.
John is in a garden. John is in a garden in the morning.
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.
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.
ACE provides alethic modality with auxiliary modals for possibility (can/cannot/can not/can't) and necessity (must/have to/does not have to). For modal sentences see Subordination.
John can wait. John cannot wait. John must wait. (= John has to wait.) John does not have to wait.
Verb phrases can be coordinated by and and by or.
John waits and eats a burger. John is rich or earns his own income.
Verb phrases — with the exception of the copula be — can be modified by adverbs. All verbs — including the copula be — can be modified by prepositional phrases.
Adverbs and prepositional phrases follow the verb and its complements (if present).
John is a rich customer in England . John is rich in the beginning. A customer is in his own office. A student is interested in a classroom. A customer waits in a bank in the morning. A customer inserts a card manually. A customer inserts a card manually into a slot.
Adverbs can alternatively precede the verb.
A customer manually inserts a card. A customer manually inserts a card into a slot.
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 inserts a card in the bank at a time T. A customer inserts a card carefully into the slot. A customer inserts a card in the bank carefully into the slot. John is a rich customer in England in the current year.
In that-subordination (Subordination) modifiers of the verb of the main phrase must occur immediately before the word that.
John believes seriously in the morning that Mary fills-in a form.
Simple sentences have the structure
noun phrase + verb + complements + adjuncts
Complements are direct and indirect objects (i.e. noun phrases). Adjuncts are optional adverbs and prepositional phrases. Additionally, adverbs can also precede the verb.
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.
In addition to the general sentence structure, it is possible to create well-formed sentences without a verb, by using the there is/are construction.
there is/are + noun phrase
This construct only introduces objects into the discourse. For this reason noun phrases following there is/are cannot be and cannot contain definite noun phrases, proper names, numbers, arithmetic expressions, strings, sets, or lists — that are introduced by their mere appearance. For the same reason it is also not possible to use complements and adjuncts.
There is a customer. There is some water. There are more than 6 clerks. There are a cat and 2 dogs. There are a cat and at most 2 dogs.
Also Boolean formulas count as sentences. They are built from numbers and arithmetic expressions with the help of the comparison operators =, \=, >, >=, < and =<. Formulas are not evaluated by the parser.
10 = 4 + 6. X \= 2. 5 > 3. X >= 13.4.
Composite sentences are recursively built from simpler sentences with the help of predefined constructors.
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.
There are existential and universal local quantification.
For the treatment of the semantics of quantifiers in ACE, see the ACE interpretation rules. Note that universal quantification can also be expressed by an if ... then construct.
There is a card. There is some water. There are at least 2 cards. John enters a card. John drinks some water. 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.)
There are existential and universal global quantification in which the quantifiers are moved to sentence initial position.
existential quantification: there is/are ... that ..., there is/are ... such that ... universal quantification of countable nouns: for every/each, for each of universal quantification of mass nouns: for all
There is a code that every clerk enters. There is a code such that every clerk enters it. For every code a clerk enters it. For each code there is a clerk such that he enters it. For each of 3 men there is a bed. For all water there is a container.
ACE knows five forms of sentence subordination:
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.
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 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 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 (not) possible/necessary 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.
In that-subordination a verb takes a complete sentence as an object.
A clerk believes that a customer inserts a card.
For that-subordination, _that_ can be used instead of that. This is needed for the cases where the subordinating that can be confused with the relative pronoun that (consult the ACE interpretation rules for details). Here is an example.
A manager knows in the morning that a clerk oversleeps.
ACE allows two simple forms of interrogative sentences: yes/no queries and wh-queries.
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.
Who waits? Who wait? (= Who waits?) Each of who waits? What does a man not eat? A card of who is valid? Who does John not see? Which customer enters a card and types a code? How does John enter a card? Where does John wait? When does John wait? There is who? There is which man? Where is John? Whose dog barks?
ACE supports simple imperative sentences.
John, go to the bank! John and Mary, wait! Every dog, bark! A brother of John, give a book to Mary!
A command has to end with an exclamation mark. It consists of a noun phrase (the addressee), followed by a comma, followed by an uncoordinated verb phrase.
An ACE text is a sequence of anaphorically interrelated declarative sentences (simple sentences or composite sentences). Each sentence must end with a full stop.
Mary enters a card into a machine. Its screen blinks or Mary waits.
ACE queries can consist of any number of declarative sentences followed by one interrogative sentence. The interrogative sentence must end with a question mark.
Mary enters a card into a machine. Its screen blinks or John waits. A screen of what blinks? There is a man. He waits. Does he sleep?
ACE 6.0 allows the definition of sentential macros and references to these macros. A macro definition introduces the name of the macro and its defining sentence. The definition consists of the word proposition followed by the name of the macro followed by a colon. After the colon follows the defining ACE sentence. ACE sentences refer to a macro via its name. Macro expansion is the substitution of the name of a macro by its defining sentence; any anaphoric references occurring in the defining sentence are resolved after the substitution.
Proposition P: A card is correct.
Defined macros can be referred to by their names. A macro is referred to when its name is inserted after the word that of any of the sentence-initial phrases or of sentence subordination. Here are some examples.
It is true that P. It is false that P. It is possible that P. It is not provable that P. A customer believes that P.
Each occurrence of a macro name is replaced by its defining sentence; then any anaphors occurring in the defining sentence are resolved.
For the often occurring case
Proposition P: A card is correct. It is true that P.
the abbreviation
Fact P: A card is correct.
can be used.
Definitions of macros can refer to previously defined macros.
Proposition P: A card is correct. Proposition Q: A customer believes that P.
Macro names and variables associated with noun phrases cannot be confused since they are defined and called in syntactically different contexts.
2008-01-19