Re: [Bug-apl] recursive functions - ackerman

[Fausto Saporito]

Hi Fred,

thanks a lot.

Now it works... but (maybe it's a stupid question) why that change? :-)

regards,

Fausto

2015-04-15 22:37 GMT+02:00 Frederick H. Pitts <address@hidden>:

Fausto,

        Try changing the fourth line to

z←(m-1) ack (m ack (n-1))⋄ →0

Regards,

Fred

On Wed, 2015-04-15 at 21:03 +0200, Fausto Saporito wrote:
> Hello all,
>
>
> I'm trying to implement ackerman function, but I got no luck ... and I
> cannot understand why this code doesn't work:
>
> z←m ack n
> →(m=0)/∆1
> →(n=0)/∆2
> z←(m-1) ack (m ack (n-1))
> ∆1: z←n+1 ⋄ →0
> ∆2: z←(m-1) ack 1
>
>
> is the double recursion permitted in APL2 ?
>
>
> thanks,
>
> fausto
>
>