040000 tree 63f33be2050fa4d26596434c94af2ca44005fcbc	concepts.callable
040000 tree 1d6dc0cd23cd617d163e8b62577d44c8f4c14059	concepts.compare
040000 tree bac58dceb5ee9b4a7d9c89df64aa57e9b84f2ae4	concepts.lang
040000 tree ac724d10c16bcf6c482ed6dabb09865e31e48ee9	concepts.object