[fpc-pascal] undefining multiple defines

[Marc Santhoff]

Hi,

I'm using several defines like this:

{$define M1}
{ $define M2}
{ $define M3}
{ $define M4}
...

Any time I have to change them, I have to touch all one by one, because
they're mutually exclusive.

Is there method of saying: {$undef M1..M15}?
Or a better basic approach? 

TIA,
Marc