First, while it’s reasonable to expect a good test suite to detect almost all the mutants added to a program, it isn’t reasonable to expect a static analysis tool to do so; many bugs cannot be detected statically. A handful of really obvious problems were detected by all three tools, but these 18 mutants amount to less than 0.5% of all detected mutants. We’re proud that Slither detected both the most mutants overall and the most mutants that only it detected.