| author | wenzelm |
| Sat, 01 Dec 2001 18:52:32 +0100 | |
| changeset 12338 | de0f4a63baa5 |
| parent 9015 | 8006e9009621 |
| child 13208 | 965f95a3abd9 |
| permissions | -rw-r--r-- |
| 9015 | 1 |
(* type inference *) |
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Type = Func + |
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types ty |
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12338
de0f4a63baa5
renamed class "term" to "type" (actually "HOL.type");
wenzelm
parents:
9015
diff
changeset
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arities ty :: type |
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consts bool :: ty |
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nat :: ty |
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"->" :: ty => ty => ty (infixr 20) |
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typeof :: [tm, ty] => bool |
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anyterm :: tm |
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rules common_typeof " |
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typeof (app M N) B :- typeof M (A -> B) & typeof N A.. |
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typeof (cond C L R) A :- typeof C bool & typeof L A & typeof R A.. |
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typeof (fix F) A :- (!x. typeof x A => typeof (F x) A).. |
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typeof true bool.. |
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typeof false bool.. |
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typeof (M and N) bool :- typeof M bool & typeof N bool.. |
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typeof (M eq N) bool :- typeof M T & typeof N T .. |
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typeof Z nat.. |
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typeof (S N) nat :- typeof N nat.. |
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typeof (M + N) nat :- typeof M nat & typeof N nat.. |
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typeof (M - N) nat :- typeof M nat & typeof N nat.. |
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typeof (M * N) nat :- typeof M nat & typeof N nat" |
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rules good_typeof " |
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typeof (abs Bo) (A -> B) :- (!x. typeof x A => typeof (Bo x) B)" |
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rules bad1_typeof " |
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typeof (abs Bo) (A -> B) :- (typeof varterm A => typeof (Bo varterm) B)" |
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rules bad2_typeof " |
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typeof (abs Bo) (A -> B) :- (typeof anyterm A => typeof (Bo anyterm) B)" |
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end |