It’s from VectorSpace; sorry, spaced on passing that along. Here’s some other code with the functions written out by hand. <|> is the inner product of the two vectors. `x.class`

returns `Float`

```
a = [3,-2];
b = [3,-2];
~innerProduct = {|vec1, vec2| (vec1[0] * vec2[0]) + (vec1[1] * vec2[1])}; // define inner product
~norm = {|vec| vec[0].sumsqr(vec[1]).sqrt}; // define norm
x = ~innerProduct.(a,b) / (~norm.(a) * ~norm.(b)); // do it by hand
acos(x); // nan
acos(1.0); // 0.0
x == 1.0; // false
```

I think @totalgee is right; `x == 1.0`

returns `false`

. `x-1`

returns `2.2204460492503e-16`

. Is there a way to check when a value not quite 1.0?