🚀 go-pugleaf

On 25/02/2018 19:08, JimP wrote:
> On Sun, 25 Feb 2018 15:30:39 +0000, Andrew Swallow
> <am.sw...@btinternet.com> wrote:
> 
>> On 24/02/2018 14:35, JimP wrote:
>>> On 24 Feb 2018 08:29:08 GMT, Jorgen Grahn <grahn...@snipabacken.se>
>>> wrote:
>>>
>>>> On Sat, 2018-02-24, Charlie Gibbs wrote:
>>>>> On 2018-02-23, hanc...@bbs.cpcn.com <hanc...@bbs.cpcn.com> wrote:
>>>>>
>>>>>> Personally, I think all programmers, whatever their specialty,
>>>>>> should have a solid background in algebra.  IMHO, if someone
>>>>>> is weak in algebra, they'll be a weak programmer.
>>>>
>>>> That's the stance my university took, around 1990.  You didn't get to
>>>> do computer science until after some hefty maths courses (where most
>>>> of the students dropped off).
>>>>
>>>>> Better still, a solid background in logic.
>>>>
>>>> I think of it as having a talent for working within systems of rules.
>>>> Maths is a good way to exercise that talent.  I suppose board games
>>>> are too, but I'm a lousy player.
>>>>
>>>> But I'm not sure ... nowadays I tend to think of programming as a
>>>> craft.  I never used much of my formal training, and some of the best
>>>> programmers I've worked with had none.
>>>>
>>>>> Any programmer worth his salt should know about De Morgan's theorem,
>>>>> whether he knows its name or not.
>>>>
>>>> I had forgotten the name, but yes.
>>>>
>>>> /Jorgen
>>>
>>> I looked it up... never used it in any programming class, and never
>>> used it to repair a computer. I had to take a math minor so I probably
>>> had it in algebra. Don't remember it from the calculus classes I took,
>>> I have gladly forgotten my calculus.
>>>
>>
>> De Morgan's theorem is Boolean algebra. The ability to change
>>
>> IF age > max_age OR age < min_age THEN
>>    CALL report_age_wrong
>> ELSE
>>    candidate_age = age
>> ENDIF
>>
>> into
>>
>> IF age <= max_age AND age >= min_age THEN
>>    candidate_age = age
>> ELSE
>>    CALL report_age_wrong
>> ENDIF
> 
> I have used Boolean; however, the example I found was two circles A
> and B and their overlap. Thats sets. I did one program dealing with
> sets at junior college in Apple Fortran 1.0, but none in my university
> work with VAX PASCAL on a DEC VAX 11/730.
> 

Boolean algebra is based around the set of {true, false} frequently 
written {1, 0} with operators {And, Or, Not} plus in the real world {Set 
to 1, Set to 0, Input, Output}

In computer languages the Boolean operators are {And, Or, Not, Set true, 
Set false, assign, >, <, ==, /=, >=, <=}

Two variables are only the starting point when teaching Boolean algebra.