Test condition 0< var <1

Hello,

I tried using the [if...] fonction to test if a value is between 0 and 1 this way :

[if $f1 > 0. || $f1 < 1. then $f1 else 0.]

and it doesn't work

[if $f1 > 0. || $f2 < 1. then $f1 else 0.] works

But I can't find out how to make two test on the same $f1

Thanks )