src/ZF/Sum.thy
 author paulson Fri Jan 03 15:01:55 1997 +0100 (1997-01-03) changeset 2469 b50b8c0eec01 parent 1478 2b8c2a7547ab child 3923 c257b82a1200 permissions -rw-r--r--
Implicit simpsets and clasets for FOL and ZF
```     1 (*  Title:      ZF/sum.thy
```
```     2     ID:         \$Id\$
```
```     3     Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
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```     4     Copyright   1993  University of Cambridge
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```     5
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```     6 Disjoint sums in Zermelo-Fraenkel Set Theory
```
```     7 "Part" primitive for simultaneous recursive type definitions
```
```     8 *)
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```     9
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```    10 Sum = Bool + pair +
```
```    11 consts
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```    12     "+"         :: [i,i]=>i                     (infixr 65)
```
```    13     Inl,Inr     :: i=>i
```
```    14     case        :: [i=>i, i=>i, i]=>i
```
```    15     Part        :: [i,i=>i] => i
```
```    16
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```    17 defs
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```    18     sum_def     "A+B == {0}*A Un {1}*B"
```
```    19     Inl_def     "Inl(a) == <0,a>"
```
```    20     Inr_def     "Inr(b) == <1,b>"
```
```    21     case_def    "case(c,d) == (%<y,z>. cond(y, d(z), c(z)))"
```
```    22
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```    23   (*operator for selecting out the various summands*)
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```    24     Part_def    "Part(A,h) == {x: A. EX z. x = h(z)}"
```
```    25 end
```