1 consts normif :: ifex => ifex => ifex => ifex
2 primrec
3 "normif (CIF b) t e = IF (CIF b) t e"
4 "normif (VIF x) t e = IF (VIF x) t e"
5 "normif (IF b t e) u f = normif b (normif t u f) (normif e u f)"