There are numerous new features from 0.13 to 0.18, including improved support for more backends, SystemVerilog and Verific.
For a complete list of changes, please see https://github.com/YosysHQ/yosys/releases

• passed all cases in the check step;
• install, run example in examples/osu035 with make, see result file example.edif.
• run example in examples/python-api, check if it produces a plot.