I am working in the

sky130tech

file and would like to initialize the DRC rules in terms of lambda (λ). Specifically, I want to define lambda as 0.04µm and ensure that certain rules, such as the metal width, are written in terms of multiples of lambda. For example, how can I write a DRC rule to enforce that the metal width must be greater than 5λ (5 times lambda)? Could anyone guide me on how to structure this rule?

If you want to use magic, your best chance is to look into libs.tech/magic/sky130B.tech and find the DRC rules. It's likely possible to replace hard coded variables by formulas including lambda, not sure about .tech magic syntax and its possibilities. In case you want a KLayout DRC deck best starting point is gf180mcu "libs.tech/klayout", it's based on python and produce nice output for finding DRC in the layout.