Module ExtrFacts := GenExtrFacts (Def) (Conseq) (Extr).

Theorem semax_cast_load_backward: forall {CS: compspecs} {Espec: OracleKind} (Delta: tycontext),
forall (P: environ->mpred) id e,
@semax CS Espec Delta
(EX sh: share, EX e1: expr, EX t1: type, EX v2: val,
!! (e = Ecast e1 t1 /\
typeof_temp Delta id = Some t1 /\
cast_pointer_to_bool (typeof e1) t1 = false /\
readable_share sh) &&
|> ( (tc_lvalue Delta e1) &&
local (`(tc_val t1) (`(eval_cast (typeof e1) t1 v2))) &&
(`(mapsto sh (typeof e1)) (eval_lvalue e1) (`v2) * TT) &&
subst id (`(force_val (sem_cast (typeof e1) t1 v2))) P))
(Sset id e) (normal_ret_assert P).