HLL – High Level Language

HLL crash course for Safety Engineers

Beginning May 18th, I led a four-day online crash course on HLL for a dozen Safety Engineers. Due to the French COVID-19 lockdown, the course was conducted via Microsoft Teams, alternating lectures and exercises. An online course is a very special experience: you can get very close to a student’s activities when sharing terminals and [...]

By |2020-06-10T07:27:51+01:00June 10th, 2020|Formal Verification, HLL – High Level Language|

HLL Forum takes the step of creating an official language definition for HLL 3.0!

On November 21st, we met at the office of Ikos Consulting in Levallois-Perret. In the presence of the creators, the designers, and the users of the language, we agreed about future enhancement processes and started the process to precisely define the next version of the HLL language definition. The next steps will be to concretely [...]

By |2019-11-25T09:22:11+01:00November 24th, 2019|HLL – High Level Language|

Using HLL to solve Sudoku puzzles

In a recent post we celebrated the 10th anniversary of the declarative, formal language HLL. The language is used extensively in the railway signaling domain for the formal verification of interlocking logic and CBTC subsystems (such as zone controllers). In this more technical post we will familiarize the reader further with HLL, by formalizing the famous [...]

By |2019-07-11T09:08:21+01:00July 10th, 2019|Formal Methods, HLL – High Level Language|

HLL formal language celebrates 10 years

The formal language HLL (High Level Language) has emerged in recent years as a quite popular language for formal verification of safety-critical systems, especially in the railway signaling domain. This year marks the 10th anniversary of its conception. The history of HLL The language has its roots in the proof engine technologies developed by Prover in the 1980s (Stålmarck's [...]

By |2019-07-03T09:25:55+01:00June 30th, 2018|Formal Methods, HLL – High Level Language|