# Re: [julia-users] Horn clauses

```The negation I'm guessing would be x = false, iff an equivalence of type
and value (but in Julia?), implication a combination of if x = true then y
= false? Is it as simple as this? ```
```
On Tuesday, September 20, 2016 at 11:56:46 AM UTC-3, Kevin Liu wrote:
>
> Would anyone know how to represent logical connectives (e.g. negation ¬,
> conjunction ∧, disjunction ∨, material implication ⇒, biconditional iff ⇔)
> and quantifiers (e.g. all ∀, exists ∃) in Julia?
>
> I understand 'all' can be a for loop. Is the conjunction a comma like in
> Prolog? Disjunction the 'else' of an if statement? 'Exists' an x = true?
>
> On Tuesday, September 20, 2016 at 12:31:23 AM UTC-3, Kevin Liu wrote:
>>
>> Thanks Cedric, read some of that and LilKanren.jl and this is where I am
>> with the code (attached). Will continue tomorrow. Feel a bit lost, nothing
>> out of the usual.
>>
>> On Monday, September 19, 2016 at 9:15:43 PM UTC-3, Cedric St-Jean wrote:
>>>
>>> You might want to roll your own, too. It's instructive, and not
>>> particularly hard. Russell and Norvig's textbook has a good section on it.
>>>
>>> On Monday, September 19, 2016 at 5:44:04 PM UTC-4, Kevin Liu wrote:
>>>>
>>>> Thanks for the direction, Stefan.
>>>>
>>>> On Monday, September 19, 2016 at 3:10:19 PM UTC-3, Stefan Karpinski
>>>> wrote:
>>>>>
>>>>> You might try LilKanren.jl <https://github.com/lilinjn/LilKanren.jl>.
>>>>>
>>>>> On Mon, Sep 19, 2016 at 10:21 AM, Kevin Liu <kvt...@gmail.com> wrote:
>>>>>
>>>>>> Hello. What would be the long-term solution for using Horn clauses in
>>>>>> Julia? Is the present solution to call Prolog from C and C from Julia?
>>>>>> Thanks
>>>>>>
>>>>>
>>>>>```