The code was taken from http://www.staff.science.uu.nl/~jeuri101/MSc/jwroorda/ and was updated for the current haskell-platform.
$ ghci Main.hs
*Main> main
__ __ ______ __ __ __ ______________________________________________
|| || ||_ || || || ||/ Henk 2000: Based on Pure Type Systems
||___|| ||- __ ||\ || ||\
||---|| ||__|| || \|| 2000 WWW: http://www.cs.uu.nl/~johanj/MSc/jwroorda
|| || Report bugs to: [email protected]
|| || ______________________________________________
Loading prelude.henk...
Type inferencing prelude.henk...
Numbers of errors: 0
Type checking prelude.henk...
Numbers of errors: 0
Enter name of programfile <prog.henk>:
Parsing prog.henk...
Type inferencing...
Numbers of errors: 0
Type checking...
Numbers of errors: 0
Evaluating:
map E Bool apply exList
Result:
[False,True]