Edit detail for #316 solve dies on included code revision 5 of 6

I don't know enough if this is a repeat somewhere else:

solve([x**3+y**3+cot(z)=12,x**2+z=1101,x*y=53],[x,y,z])

   There are no library operations named ** 
      Use HyperDoc Browse or issue
                                 )what op **
      to learn if there is any operation containing " ** " in its name.

   Cannot find a definition or applicable library operation named ** 
      with argument type(s) 
                                 Variable(x)
                               PositiveInteger

      Perhaps you should use "@" to indicate the required return type, 
      or "$" to specify which version of the function you need.

gave:: WARNING (genufact): No known algorithm to factor 6 3 ? + (cot(z) - 12)? + 148877, trying square-free.

>> Error detected within library code: No identity element for reduce of empty list using operation append

Similarly:

 solve([x+cot(z)=12,x+z=0],[x,z])
 2) -> 
   >> Error detected within library code:
   No identity element for reduce of empty list using operation
   append

no patch available