If  and  are nonnegative integers and F is a field, then a polynomial collection {p1, . . . , p}  Z[1, . . . ,  ] is said to be solvable over F if there exist 1, . . . ,   F such that for all i = 1, . . . , we have pi(1, . . . ,  ) = 0. We say that a network and a polynomial collection are solvably equivalent if for each field F the network has a scalar-linear solution over F if and only if the polynomial collection is solvable over F. Koetter and M							
						
							
					 															
					Randall Dougherty, Christopher F. Freiling, Kennet