| author | haftmann |
| Wed, 28 May 2008 11:05:47 +0200 | |
| changeset 26999 | 284c871d3acb |
| permissions | -rw-r--r-- |
| haftmann@26999 | 1 |
structure Nat = |
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struct |
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|
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datatype nat = Dig1 of nat | Dig0 of nat | One_nat | Zero_nat; |
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|
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fun plus_nat (Dig1 m) (Dig1 n) = Dig0 (plus_nat (plus_nat m n) One_nat) |
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| plus_nat (Dig1 m) (Dig0 n) = Dig1 (plus_nat m n) |
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| plus_nat (Dig0 m) (Dig1 n) = Dig1 (plus_nat m n) |
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| plus_nat (Dig0 m) (Dig0 n) = Dig0 (plus_nat m n) |
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| plus_nat (Dig1 m) One_nat = Dig0 (plus_nat m One_nat) |
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| plus_nat One_nat (Dig1 n) = Dig0 (plus_nat n One_nat) |
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| plus_nat (Dig0 m) One_nat = Dig1 m |
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| plus_nat One_nat (Dig0 n) = Dig1 n |
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| plus_nat m Zero_nat = m |
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| plus_nat Zero_nat n = n; |
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|
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end; (*struct Nat*) |