fact: Definition break_if_none (m : monad) (break : _) (acc : nat) (x : option nat) : m nat := if x is Some x then Ret (x + acc) else break acc.
imports: mathcomp(all_ssreflect) imonae_lib HB(structures) ihierarchy imonad_lib ifail_lib istate_lib itrace_lib imonad_transformer