src/CTT/Arith.thy
 author paulson Mon Dec 07 18:26:25 1998 +0100 (1998-12-07) changeset 6019 0e55c2fb2ebb parent 3837 d7f033c74b38 child 10467 e6e7205e9e91 permissions -rw-r--r--
tidying
```     1 (*  Title:      CTT/arith
```
```     2     ID:         \$Id\$
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```     3     Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
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```     4     Copyright   1991  University of Cambridge
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```     5
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```     6 Arithmetic operators and their definitions
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```     7
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```     8 Proves about elementary arithmetic: addition, multiplication, etc.
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```     9 Tests definitions and simplifier.
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```    10 *)
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```    11
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```    12 Arith = CTT +
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```    13
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```    14 consts "#+","-","|-|"   :: "[i,i]=>i"   (infixr 65)
```
```    15        "#*",div,mod     :: "[i,i]=>i"   (infixr 70)
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```    16
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```    17 rules
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```    18   add_def     "a#+b == rec(a, b, %u v. succ(v))"
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```    19   diff_def    "a-b == rec(b, a, %u v. rec(v, 0, %x y. x))"
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```    20   absdiff_def "a|-|b == (a-b) #+ (b-a)"
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```    21   mult_def    "a#*b == rec(a, 0, %u v. b #+ v)"
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```    22   mod_def     "a mod b == rec(a, 0, %u v. rec(succ(v) |-| b, 0, %x y. succ(v)))"
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```    23   div_def     "a div b == rec(a, 0, %u v. rec(succ(u) mod b, succ(v), %x y. v))"
```
```    24 end
```