@breandan Here you are: https://github.com/mipt-npm/kmath/blob/dimensions/kmath-dimensions/src/commonTest/kotlin/scientifik/kmath/dimensions/DMatrixContextTest.kt This is all I can do today, but it seems to be lie what you wanted. I have not tried to work with with custom dimensions, but it should work as well.

Nice, I'll take a look. Starting to explore how to use the KMath algebra for Kotlingrad, I will try to build some integration with your type system