Poly, so basically SML. The issue turned out to be that I'd accidentally deleted a pair of brackets, so my labelling of the input of a function was actually labelling its output. I just needed a second pair of eyes to look at it. Now I've got this: https://mega.co.nz/#!axISSZxC!CIKHcBTVVEnQPxOf_a00I4MrYubG75CVsE4JSg5E8uQ
OS: Windows 10 64 bit Professional
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56
