ref: f3d7e4127dbfc7876ad34dba86920d3601733358 dir: /tests/Deriving.ref/
True False False True False True True True False True False A 'a' B False C 'a' 1 D A (A 'a') R{x='a',y=10} R{x=R{x='b',y=11},y=10} Alt [True]