Replace definition with:
Summary: Calculate the yield of a bond
Syntax: YIELD( DateParam Settlement ; DateParam Maturity ; Number Rate ; Number Price ; Number Redemption ; Number Frequency [ ; Basis Basis = 0 ] )
Returns: Number
Constraints: Rate, Price, and Redemption should be greater than 0.
Semantics: The parameters are
Settlement: the settlement date of the bond
Maturity: the maturity date of the bond
Rate: the coupon rate of the bond
Price: the market price of the bond per 100 currency units face value
Redemption: the redemption value of the bond per 100 currency units face value
Frequency: the coupon payments frequency. 1=annually; 2=semiannually; 4=quarterly
Basis: the day count convention to use, see section 3.10.6
(Note that we should use the universal currency symbol '¤' (U+00A4) instead of writing "currency units"