Geoff Burn defines evaluATors E0, E1, E2 and E3 which when applied to an expression, reduce it to varying degrees. E0 does no evaluATion, E1 it evaluATes to {weak head normal form} (WHNF), E2 evaluATes the structure of a list, i.e. it evaluATes it either to NIL or evaluATes it to a CONS and then applies E2 to the second argument of the CONS. E3 evaluATes the structure of a list and evaluATes each element of the list to WHNF. This concept can be extended to dATa structures other than lists and forms the basis of the {evaluATion transformer} style of {strictness analysis}. (1994-12-12)