22. An apparatus according to claim 19 further comprising suspect expression modification means for generating a modified form of said suspect expression and for locating a database expression matching said modified suspect expression.
22. An apparatus according to claim 19 further comprising suspect expression modification means for generating a modified form of said suspect expression and for locating a database expression matching said modified suspect expression. 23. An apparatus according to claim 22 wherein said suspect expression modification means comprises means for at least one of i. generating a signal representative of an expression having a transposed character sequence, ii. generating a signal representative of an expression having a deleted character, iii. generating a signal representative of an expression having an added character, and iv. generating a signal representative of an expression having a replaced character.