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)