fact: Definition safeAcc_scanl i (us ds : seq Z) := let ok i_xus_yds := queens_ok i_xus_yds in let op i_us_ds x := queens_next i_us_ds x in all ok \o scanl op (i, us, ds).
imports: ZArith mathcomp(all_ssreflect) infotheo(ssrZ) monae_lib hierarchy monad_lib fail_lib state_lib