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-
- INFER is a simple computer program that can solve the hypothetical
- syllogism. A syllogism is a short argument form consisting of one or more
- premises and a conclusion, which is inferred from the data. Following is a
- syllogism from the time of Aristotle:
-
- Socrates is a man.
- A man is mortal.
- Therefore, Socrates is mortal.
-
- INFER has four kinds of statements -
- a) declarations,
- b) queries,
- c) requests,
- d) inquiries.
-
- Although queries, requests and inquiries are synonyms, they each have a
- different function in this program.
-
- A: Declarations
- ===============
- Data is declared in the following way -
-
- -> <noun phrase> is <noun phrase>
-
- A noun phrase consists of an optional article, optional adjectives and a
- noun, with the predicate 'is' (which must be in lower case). For example,
-
- -> Socrates is a man
- Noted
-
- -> A man is mortal
- Noted
-
-
- B: Queries
- ==========
- Queries (which are answered either 'Yes' or 'I don't know') have the
- following form -
-
- -> is <noun phrase> a <noun phrase>
-
- -> is Socrates a man?
- Yes
-
-
- C: Requests
- ===========
- Requests ask for all the data known about something, for example
-
- -> request Socrates
- Socrates is ...
- man
-
- D: Inquiries
- ============
- Inquiries receive more data than a query or a request, for example
-
-
- -> who is a man?
- Socrates is a man
-
- -> who is mortal?
- A man is mortal
-
-
- The following are rather more complex examples, and show how new relations
- can be defined in terms of previous ones.
-
-
- -> an impecunious person is a borrower of money
- Noted
-
- -> a composer is an impecunious person
- Noted
-
- -> Mozart is a composer
- Noted
-
- -> is Mozart a borrower of money?
- Yes
-
- -> is Haydn a borrower of money?
- I have no data concerning Haydn
-
- -> Haydn is a composer
- Noted
-
- -> is Haydn a borrower of money?
- Yes
-
- -> who is a borrower of money?
- composer is a borrower of money
- impecunious person is a borrower of money
- Mozart is a borrower of money
- Haydn is a borrower of money
-