The set of fixed points which do not move as a knot is transformed into itself is not a knot. The conjecture was proved in 1978 (Morgan and Bass 1984). According to Morgan and Bass (1984), the Smith conjecture stands in the first rank of mathematical problems when measured by the amount and depth of new mathematics required to solve it.
The generalized Smith conjecture considers  to be a piecewise linear 
-dimensional hypersphere
 in 
,
 and 
 the 
-fold
 cyclic covering of 
 branched along 
,
 and asks if 
 is unknotted if 
 is an 
 (Hartley 1983). This conjecture is true for 
, and false for 
, with counterexamples in the latter case provided by
 Giffen (1966), Gordon (1974), and Sumners (1975).
 
         
	    
	
    
