_Package_: coverlet.msbuild _Version_: 3.1.2 _Format_: opencover Combining the C#7 `is` with the C#9 `and` in a pattern-matching `if`, branch coverage is lower than the same check in traditional boolean logic. I created a simple repro of this because I cannot show the actual code that caused the problem (it's from my job). `is` + `and`:  Traditional:  Repro code: https://github.com/Malivil/Coverlet1313Repro