Loaded package environment from /home/liquidhaskell/liquid-server/dist-newstyle/tmp/environment.-165771/.ghc.environment.x86_64-linux-9.12.2
[1 of 1] Compiling Lecture_02_DataTypes ( resources/custom/liquidhaskell/sandbox/1772703628_1979.hs, resources/custom/liquidhaskell/sandbox/1772703628_1979.o )

**** LIQUID: SAFE (2575 constraints checked) ***********************************