or even ...

Function XNOR(ParamArray args()) As Boolean
Dim i As Long
Dim params1, params2

params1 = args(1)
For i = LBound(args) + 1 To UBound(args)
params1 = params1 And args(i)
params2 = Not params2 And Not args(i)
Next i

XNOR = params1 Or params2
End Function



Function NAND(A As Boolean, B As Boolean) As Boolean
Dim i As Long
Dim params1, params2

params1 = args(1)
For i = LBound(args) + 1 To UBound(args)
params1 = params1 And args(i)
Next i

NAND = Not params1
End Function


--

HTH

Bob Phillips
... looking out across Poole Harbour to the Purbecks
(remove nothere from the email address if mailing direct)

"Bob Phillips" wrote in message
...
Nice Vasant!

Liked it so much, I extended to multiple arguments

Function XNOR(ParamArray args()) As Boolean
Dim i As Long
Dim params1, params2

For i = LBound(args) + 1 To UBound(args)
params1 = args(i - 1) And args(i)
params2 = Not args(i - 1) And Not args(i)
Next i

XNOR = params1 Or params2
End Function



Function NAND(A As Boolean, B As Boolean) As Boolean
Dim i As Long
Dim params1

For i = LBound(args) + 1 To UBound(args)
params1 = args(i - 1) And args(i)
Next i

NAND = Not params1
End Function

--

HTH

Bob Phillips
... looking out across Poole Harbour to the Purbecks
(remove nothere from the email address if mailing direct)

"Vasant Nanavati" <vasantn *AT* aol *DOT* com wrote in message
...
Hi:

XNOR(A1,B1) can be written as:

=OR(AND(A1,B1),AND(AND(NOT(A1),NOT(B1))))

NAND(A1,B1) can be written as:

=NOT(AND(A1,B1))

These can quite easily be written as UDFs.

Function XNOR(A as Boolean, B as Boolean) As Boolean
XNOR = (A And B) Or (Not A And Not B)
End Function

Function NAND(A as Boolean, B as Boolean) As Boolean)
NAND = Not (A And B)
End Function

Regards,

Vasant.


"Professor James E. Hicks" wrote
in
message ...
My Problem:

I want to create functions in Excel that can be used in
the exact same way as built-in functions are used.

For example:
to use the AND built-in function all I need to do is to
type the following into a cell:
=AND(TRUE,FALSE) ..... or
=AND(A1,B1), where cell A1 & B1 contains Boolean values.

The following functions do not exist as built-in
functions in Exce: XNOR & NAND. I would like to write
these functions and access them in the exact same manner
as the AND function:
=XNOR(TRUE,FALSE) or XNOR(A1,B1).

Please help