In the first argument of ?apply?, namely ?hr? In the expression: apply hr id SystemF.hs:18:14: Couldn't match type ?forall a2. a2 -> a2? with ?a1 -> a1? Expected type: Sid -> a1 -> a1 Actual type: Sid -> Sid In the expression: x :: Sid -> Sid In the expression: (x :: Sid -> Sid) x =====> boxy(normal) 1825 of 4045 [0, 35, 0] cd ./boxy && '/root/builder/builder/tempbuild/build/bindisttest/install dir/bin/ghc' -fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -fno-ghci-history -c boxy.hs >boxy.comp.stderr 2>&1 Compile failed (status 256) errors were: boxy.hs:43:16: Couldn't match type ?forall b1. b1 -> b1? with ?b -> b? Expected type: (forall b1. b1 -> b1) -> b -> b Actual type: (forall b. b -> b) -> forall b. b -> b In the expression: choose id In an equation for ?qH?: qH choose id = choose id boxy.hs:43:23: Couldn't match expected type ?forall b1. b1 -> b1? with actual type ?a0 -> a0? In the first argument of ?choose?, namely ?id? In the expression: choose id boxy.hs:121:14: Couldn't match type ?forall a2 b2. Stdout " (a2 ->