040000 tree be16d68217778ea9844d4b028906c3ac4e8ee40b	flow-analysis
040000 tree 3a7387735f2e7b8e9e4689dfcb89362b63416ccd	inference
040000 tree c4f77e38ebe590959e1ae81fd52140b27ee4673f	subtyping
040000 tree d74b0b2a94ac2f1f8d9da41031e0621e043832cd	type-normalization
040000 tree 19cda14afc2cdffd9556ff84675250c959830b1e	type-variance
040000 tree ca80867faee5496bf62da7353ea73ac94828b48d	upper-lower-bounds