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1### `++dec`
3Decrement
5Decrements `a` by `1`.
7Accepts
8-------
10`a` is an atom.
12Produces
13--------
15An atom.
17Source
18------
20 ++ dec :: decrement
21 ~/ %dec
22 |= a/@
23 ~| %decrement-underflow
24 ?< =(0 a)
25 =+ b=0
26 |- ^- @
27 ?: =(a +(b)) b
28 $(b +(b))
30Examples
31--------
33 ~zod/try=> (dec 7)
34 6
35 ~zod/try=> (dec 0)
36 ! decrement-underflow
37 ! exit
41***