Graphmath.Quatern.subtract

You're seeing just the function subtract, go back to Graphmath.Quatern module for more information.
Link to this function

subtract(lhs, rhs)

Specs

subtract(quatern(), quatern()) :: quatern()

subtract(lhs, rhs) subtract two quaternions.

lhs is the first quatern

rhs is the second quatern

It returns a quatern of the form { lhs<sub>w</sub> - rhs<sub>w</sub>, lhs<sub>x</sub> - rhs<sub>x</sub>, lhs<sub>y</sub> - rhs<sub>y</sub>, lhs<sub>z</sub> - rhs<sub>z</sub> }.