mm-1057 Subject: Re: Simplifying logical proposition > I would like to know if anyone could help me understanding how Maple did the > following simpliŞcation (using bsimp): > Proposition: (not p or q) and ((q and not r) or (r and not q)) > SimpliŞed proposition: r and not p and not q My Maple 9 bsimp gives (r and not p and not q) or (q and not r) I don¹t think bsimp has been changed in years. What Maple are you using? === Subject: Re: Simplifying logical proposition > I would like to know if anyone could help me understanding how Maple did the > following simpliŞcation (using bsimp): > Proposition: (not p or q) and ((q and not r) or (r and not q)) > SimpliŞed proposition: r and not p and not q > My Maple 9 bsimp gives > (r and not p and not q) or (q and not r) > I don¹t think bsimp has been changed in years. What Maple are you using? Something must have changed since you both got different and *wrong* results. Perhaps a few other Maple users can pitch in to establish whether Maple (and, indirectly, Matlab) needs to be recalled!? btw, the correct result (via paper & pencil method) is (for x_ = not x), (q_ and r) or (q and r_) -- Dr.B.Voh ------------------------------------------------------ Applied Algorithms http://sdynamix.com === Subject: Re: Simplifying logical proposition <3F8DD8AC.53E9A542@Xsdynamix.com I would like to know if anyone could help me understanding how Maple did the > following simpliŞcation (using bsimp): Proposition: (not p or q) and ((q and not r) or (r and not q)) > SimpliŞed proposition: r and not p and not q > My Maple 9 bsimp gives > (r and not p and not q) or (q and not r) > I don¹t think bsimp has been changed in years. What Maple are you using? > Something must have changed since you both got different and *wrong* > results. I have done the problem by hand, and I stand by the answer that I got with Maple. Just because different answers were obtained does not necessarily mean that the procedure is different. It could be user error. For example, the variables p, q, or r may have been assigned values earlier in the session. > Perhaps a few other Maple users can pitch in to establish > whether Maple (and, indirectly, Matlab) needs to be recalled!? > btw, the correct result (via paper & pencil method) is (for x_ = not x), > (q_ and r) or (q and r_) Your answer is wrong. It is immediately suspicious because it does not depend on p, whereas the original expression only has a single p, so is very likely to depend on p. Evaluate the original expression and your expression with the assignment [p=true, q=false, r=true]. The original will be false, and yours will be true. I wish that the OP would respond with how he got Maple to give the answer that he got. === Subject: Re: Simplifying logical proposition <3F8DD8AC.53E9A542@Xsdynamix.com> (q_ and r) or (q and r_) > Your answer is wrong. It is immediately suspicious because it does not > depend on p, whereas the original expression only has a single p, so is > very likely to depend on p. Evaluate the original expression and your > expression with the assignment [p=true, q=false, r=true]. The original > will be false, and yours will be true. You¹re right, I have overlooked the wrapped column in the posted truth table and derived the expression from a wrong column. Oh, well... -- Dr.B.Voh ------------------------------------------------------ Applied Algorithms http://sdynamix.com === Subject: Re: Simplifying logical proposition btw, the correct result (via paper & pencil method) is (for x_ = not x), > (q_ and r) or (q and r_) > Your answer is wrong. It is immediately suspicious because it does not > depend on p, whereas the original expression only has a single p, so is > very likely to depend on p. Evaluate the original expression and your > expression with the assignment [p=true, q=false, r=true]. The original > will be false, and yours will be true. > You¹re right, I have overlooked the wrapped column in the posted truth > table and derived the expression from a wrong column. Oh, well... Sorry about that. I thought it would not wrap but I must have miscounted columns.