1delconst NONE
2delconst SOME
3delconst IS_SOME
4delconst IS_NONE
5delconst OPTION_MAP
6deltype option
7skipthm option_TY_DEF
8skipthm datatype_option
9skipthm option_REP_ABS_DEF
10skipthm NONE_DEF
11skipthm SOME_DEF
12delproof option_Axiom
13delproof option_induction
14delproof option_nchotomy
15delproof SOME_11
16delproof NOT_NONE_SOME
17delproof NOT_SOME_NONE
18