- IS_SUM_REP
-
|- !f.
IS_SUM_REP f =
(?v1 v2. (f = (\b x y. (x = v1) /\ b)) \/ (f = (\b x y. (y = v2) /\ ~b)))
- sum_TY_DEF
-
|- ?rep. TYPE_DEFINITION IS_SUM_REP rep
- sum_ISO_DEF
-
|- (!a. ABS_sum (REP_sum a) = a) /\
(!r. IS_SUM_REP r = REP_sum (ABS_sum r) = r)
- INL_DEF
-
|- !e. INL e = ABS_sum (\b x y. (x = e) /\ b)
- INR_DEF
-
|- !e. INR e = ABS_sum (\b x y. (y = e) /\ ~b)
- ISL
-
|- (!x. ISL (INL x)) /\ (!y. ~(ISL (INR y)))
- ISR
-
|- (!x. ISR (INR x)) /\ (!y. ~(ISR (INL y)))
- OUTL
-
|- !x. OUTL (INL x) = x
- OUTR
-
|- !x. OUTR (INR x) = x