H.LL is the input language of our tool Prover Certifier. By translating your system to HLL and defining your safety requirements in HLL, you can use Prover Certifier to get safety evidence for the system. Formal verification ensures that your system fulfills the requirements in 100% of the possible scenarios, a coverage that can never be achieved by testing.
Since 2008, HLL has been used by many of our customers to obtain formal safety proofs on a level of CENELEC EN50128 SIL4.
The success of HLL can possibly be attributed to its ease of use (flexible and intuitive) coupled with the support by formal verification tools that are able to handle large industrial systems, and provide certifiable results.
There is a proposal for version 4.0 of HLL. A version 4.0 will eventually be published within the HLL Forum initiative.