:Under the definition of meta-solipsism (x)[x=x ® (x Î M)]  which simply says "Everything is in me (M)"  speaking of your meta-solipsism (M1) and my meta-solipsism (M2) as distinguishable properties leads to contradiction. Proof: 

 ::Premises of differential meta-solipsisms 

 ::1. (x)[x=x ® (x Î M1)] 
 ::2. (x)[x=x ® (x Î M2)] 
 ::3. $x(x Î M1) & $x(x Î M2) 
 ::4. M1 ¹ M2 

 ::Now, by premises 3 and 4, there exists some x such that either x Î M1 and x Ï M2 OR  x Ï M1 and x Î M2. But then we contradict either premise 1 or 2. Therefore, there cannot be different "meta-solipsisms." QED 

 :So a listing of different meta-solipsisms (as suggested "M1, M2, M3, ...") is inconsistent with meta-solipsism, premises of which we could express as (where U = the universe, and the capital X in premise 4 is a predicate variable): 

 ::Premises of meta-solipsism 

 ::1. (x)[x=x ® (x Î M)] 
 ::2. (x)[x=x ® (x Î U)] 
 ::3. M = U 
 ::4. (X)(x)[(x Î X)  ® (x Î M)] 

 :While that set of statements may be a valid logical theory (if no contradiction can be derived from it), it's just an empty definition routine, a name game  solipsist: "I call the universe 'me.'" The solipsist's name game classifies all observations as "me" a priori, and thus by definition excludes the possibility of counter example, and so is nonfalsifiable (ie, is nonscientific).