Re: Strange Solve result after previous bad input

*To*: mathgroup at smc.vnet.net*Subject*: [mg100956] Re: Strange Solve result after previous bad input*From*: Pillsy <pillsbury at gmail.com>*Date*: Thu, 18 Jun 2009 20:46:47 -0400 (EDT)*References*: <h1d4ao$o0q$1@smc.vnet.net>

On Jun 18, 6:19 am, Alain Cochard <al... at geophysik.uni-muenchen.de> wrote: [...] > Here, there is '=' instead of '==' in the 2nd eq: > In[2]:= Solve[{a==x + y, b=-x + y},{x,y}] > Solve::eqf: -x + y is not a well-formed equation. [...] > Is this normal? Yes. Here, because you used "=" where you meant to use "==", you've assigned the value -x + y to the variable b. > If so, is there a cure (some "resetting" procedure), apart from > quiting Mathematica and entering back? Yes, Unset b, like so: b = . Cheers, Pillsy