imposing check constraint on table

[LKBrwn_DBA]

Try it this way:

Create Table Classes 
(
  Class          Varchar2(10)
, Ship_Type      Char(1)
, Numguns        Number(3)
, Bore           Number(3)
, Displacement   Number(5,1)
, Constraint     Check_Bore
                 Check ((Bore < 14 And Numguns > 8 )
                    Or  (Bore > 0 And Numguns < 9 ))
                 Enable
)
/