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Takes any number N from stack and returns NOT(N).
Any number of absolute value not zero returns zero,
zero returns one.
Preserves stack.

Can anyone find a more economical version while preserving the stack?

Code:

    LBL N

    STO H

    CLx

    1-ABS(SGN(H))

    RTN

N: LN = 28

YES!

But not good for small values, eg input of 0.00000001.

Code:

1.    LBL N

2.    COS

3.    IP

4.    RTN

N: LN = 12

But fastest is

Code:

    LBL N

    SGN

    ABS

    STO H

    CLx

    1

    RCL- H

    RTN

N: LN = 36

It's fascinating to see a trig function in one of the codes.

Gerald H

Gerald H

Eddie W. Shore