foreword	news	documentation	implementation
			Version 2	Background	Core	Applications
			Version 1

• June 2014. First communication on λδ version 2.

• December 2012. The character "_" is removed from the denomination "lambda_delta":
  • The denomination "\lambda\delta" is used in λδ-related texts.
  • The denomination "lambdadelta" is used in λδ-related identifiers.
  • Permanent λδ URL acquired: http://lambdadelta.info/ (pointing at this site).

• September 2011. The denomination "lambda-delta" changes to "lambda_delta":
  • The character "-" is reserved in λδ textual syntax (recognized by "Helena 0.8.1").
  • Eventually, the occurrences of the character "-" will be replaced by "_" in all λδ-related identifiers.
  • In particular, this refactoring involves file names and path names.

• April 2011. The specification of λδ version 2 and related topics is restarted in Matita 0.5.

• December 2010. Transient λδ URL acquired: http://lambda-delta.info/ (expires on December 2012).

• November 2010. "Helena 0.8.1" is released.

• September 2009. "Helena 0.8.0" is released and the λδ Digital Library is started.

• June 2009. "Helena", a validator for λδ version 2, is available as a part of the HELM software.

• September 2008. This site is online.

• July 2008. First journal paper on λδ accepted for publication.

• July 2008. First procedural reconstruction for Matita 0.5 of the λδ version 1 for Coq 7.3.1.

• June 2008. The HTML pages of the specification of λδ version 1 for Matita 0.5 are online.

• May 2008. The specification of λδ version 1 is dismissed.

• March 2008. The specification of λδ version 2 is started with Coq 7.3.1 (false start).

• September 2007. The specification of λδ version 1 for Matita 0.4 is online.

• November 2006. λδ version 1 is released.

• December 2005. First communication on λδ.

• May 2004. The specification of λδ version 1 is started with Coq 7.3.1.

• June 2014. The Google search for "formal system lambda delta" gives 5 resources about λδ in the first 6 results.

• June 2014. The Yahoo search for "formal system lambda delta" gives 4 resources about λδ in the first 5 results.