Re: comparing rewite rules

*To*: mathgroup at smc.vnet.net*Subject*: [mg78368] Re: comparing rewite rules*From*: dimitris <dimmechan at yahoo.com>*Date*: Fri, 29 Jun 2007 05:47:12 -0400 (EDT)*References*: <f5vsg8$l2f$1@smc.vnet.net>

dbsearc... at yahoo.com : > Hello Mathematica UG: > > I input these 2 simple rewrite rule sets into Mathematica V5: > > - {yy -> 4, y -> 3} > > - {y -> 3, yy -> 4} > > I just want to compare these 2 simple rules for equality. I tried: > > - define each one and use % == %% (this just gives: {yy -> 4, y -> 3} > == {y -> 3, yy -> 4} ) > - making a symbol for each rule set and using ==, such as rul0 == > rul1, > it just echoes my input > > I also tried to replace the rules in an expression. If the replaced > result evaluates to a simple expression, it is OK but, it still fails > sometime when Mathematica reorders expressions, such as when x-1 becomes -1 + > x > > Is it possible to determine in my code that 2 "rule lists" are the > same? > > Of course, in the general case, I will have many more rules than just > these 2 small lists (e.g. Solve[] output). > > Thanks in advance. > > Regards..Roger In[8]:= o1 = -{yy -> 4, y -> 3} o2 = -{y -> 3, yy -> 4} Sort /@ {o1, o2} Equal @@ % Out[8]= {-(yy -> 4), -(y -> 3)} Out[9]= {-(y -> 3), -(yy -> 4)} Out[10]= {{-(y -> 3), -(yy -> 4)}, {-(y -> 3), -(yy -> 4)}} Out[11]= True