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(* Title: HOL/MiniML/MiniML.thy
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ID: $Id$
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Author: Dieter Nazareth and Tobias Nipkow
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Copyright 1995 TU Muenchen
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Mini_ML with type inference rules.
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*)
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MiniML = Type +
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(* expressions *)
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datatype
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expr = Var nat | Abs expr | App expr expr
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(* type inference rules *)
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consts
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has_type :: "(type_expr list * expr * type_expr)set"
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syntax
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"@has_type" :: "[type_expr list, expr, type_expr] => bool"
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("((_) |-/ (_) :: (_))" 60)
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translations
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"a |- e :: t" == "(a,e,t):has_type"
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inductive "has_type"
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intrs
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VarI "[| n < length a |] ==> a |- Var n :: nth n a"
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AbsI "[| t1#a |- e :: t2 |] ==> a |- Abs e :: Fun t1 t2"
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AppI "[| a |- e1 :: Fun t2 t1; a |- e2 :: t2 |]
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==> a |- App e1 e2 :: t1"
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end
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