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Text File | 1997-08-18 | 362 b | 20 lines | [TEXT/R*ch] |
- datatype 'a Tree =
- Lf
- | Br of 'a * 'a Tree * 'a Tree
- ;
-
- val t1 = Br(2, Br(1, Lf, Lf), Br(3, Lf, Lf));
-
- fun foldTree f u Lf = u
- | foldTree f u (Br(a, left, right)) =
- f a (foldTree f u left) (foldTree f u right)
- ;
-
- fun revBranch a left right = Br(a, right, left);
-
- local
- val reflect = foldTree revBranch Lf;
- in
- val refl_t1 = reflect t1;
- end
-