Re: Strange Output!!!Please help me thank you.
- To: mathgroup at smc.vnet.net
- Subject: [mg98833] Re: Strange Output!!!Please help me thank you.
- From: olfa <olfa.mraihi at yahoo.fr>
- Date: Mon, 20 Apr 2009 01:33:44 -0400 (EDT)
- References: <gs6pfe$h1o$1@smc.vnet.net> <gs9ei8$mq5$1@smc.vnet.net>
On 17 avr, 10:27, "Sjoerd C. de Vries" <sjoerd.c.devr... at gmail.com> wrote: > Combine both Reduces: > > Reduce[{Element[{i, j}, Integers], i <= iP, j >= jP, j + i == jP = + = > iP, > Element[{n, iP}, Integers], Not[(iP < n)], > Exists[{iPP}, (iPP < n) && iP == iPP + 1]}, {iP, jP}, > Backsubstitution -> True] > > Cheers -- Sjoerd > > On Apr 16, 10:15 am, olfa <olfa.mra... at yahoo.fr> wrote: > > > > > Hi Mathematica community, > > I have to solve this system: > > Reduce[{Element[{i, j}, Integers], i <= iP, j >= jP, > > 1*j + 1*i == 1*jP + 1*iP, > > Reduce[{Element[{N, iP}, Integers], Not[(iP < N)], > > Exists[{iPP}, (iPP < N) && iP == iPP + 1]}]}, {iP, jP}, > > Backsubstitution -> True] > > > the output should be:( i | j | N | iP) are Integers && i <= N && iP = == > = > > N && > > jP == i + j - N > > but mathematica gave me this output: > > (C[1] | C[2] | C[3] | C[4]) are Integers && C[1] >= 0 && > > C[2] >= 0 && C[3] >= 0 && C[4] >= 0 && i == C[1] - C[2] - = C[= > 3] && > > iP == C[1] - C[2] + C[4] && N == C[1] - C[2] + C[4] && > > jP == j - C[3] - C[4] > > > which is not understandable at all! and I dont want the output to be > > like that. > > > I have observed that when I remove i from Element[{i, j}, Integers] > > mathematica give me the output I want and which is :iP == N && j= P = > == > > i + j - N > > > So how can I have this same output without removing i from Element[{i, > > j}, Integers]? > > > Thank you very much in advance.- Masquer le texte des messages pr=E9c= =E9dents - > > - Afficher le texte des messages pr=E9c=E9dents - Hi Sjoerd, Yes it works but I need to have 2 reduce because my system can be more complicated than that and consequently one reduce won't be sufficient. For example when I add some equations to my system and keep only one reduce as you suggest. mathematica can't solve it. So I need 2 reduce. Is there another possibility to avoid having this kind of output: (C[1] | C[2] | C[3] | C[4]) are Integers && C[1] >= 0 && C[2] >= 0 && C[3] >= 0 && C[4] >= 0 && i == C[1] - C[2] - C[3] &= & iP == C[1] - C[2] + C[4] && N == C[1] - C[2] + C[4] && jP == j - C[3] - C[4] ?