Subtracting alphas problem

I have two world aligned blends, one controls the height of the snowline, the other is where the rock faces are(where no snow should be).

The idea I had was to subtract the rock face blend from the snow line blend. The following image shows:

Top - snowline alpha
Mid - the rock faces (where I DONT want snow)
Bot - the result of subtracting the mid from the top. This is obviously not what I expected. Notice the bare valley of grass is now covered in snow.

Here is my material:

I tried using the Clamped input and various other things but none seemed to work.

I’m willing to try other ideas to achieve the same effect as well.

Hi!

Subtraction is not right way. Because you can get undesired value like negative value or added value. For excluding some regions in mask, you need use multiplying.

Thanks svv3dUDN. I actually just figured this out and got an ok solution. I did not use multiply, was able to lerp together both masks as one minus, and used the alpha of the gradient one as mask.

The other thing I found out was you do need a Static Bool in the Clamped input set to true for this to work.